by Andrew Grimes | Sep 24, 2026 | ALL
https://youtu.be/VSRHuavnVN4
Understanding how devices communicate within a network is an important part of building a strong networking foundation. Two concepts that come up frequently are network broadcasts and local area networks (LANs).
What Is a Network Broadcast?
There are times when a computer needs to communicate with all of the other devices on a network. This type of communication is called a broadcast.
With a hub, information that comes in through one port is forwarded out through all of the other ports. Every connected device receives the information, but that doesn’t necessarily mean every device will process it.
For example, if one device sends a message to a specific MAC address, all of the devices may receive the frame when a hub is being used, but only the device with the matching destination MAC address will pay attention to it.
A switch handles normal device-to-device communication differently, but there are still times when a message needs to be sent to every device on the network.
The Broadcast MAC Address
Ethernet provides a specific MAC address for broadcasts. The broadcast address consists of all Fs:
FF:FF:FF:FF:FF:FF
When a device sends a frame using this destination address, the message is intended for all devices on the network. Devices recognize the broadcast address and process the frame because the message is specifically addressed as a broadcast.
Broadcasting is an important part of how devices communicate within a network.
What Is a LAN?
Another fundamental networking concept is the LAN, or Local Area Network.
A LAN is a local network where devices have connectivity to one another. When we look at a group of interconnected devices, such as computers connected through a hub or switch, we are looking at a LAN.
There are also different ways the term LAN can be discussed. There is the concept of a LAN, meaning the local network itself, and there are protocols and standards that define how LANs communicate.
For the purposes of understanding networking, it is useful to start with the basic concept: a LAN connects devices together within a local area.
Collisions Within a LAN
LANs can be associated with network collisions, particularly when hubs are used.
A hub sends incoming information out to the other connected devices. If multiple devices attempt to communicate at the same time, their transmissions can collide. This is referred to as a collision domain.
Replacing a hub with a switch can largely eliminate these types of collisions.
That doesn’t mean that every LAN has collisions. Rather, collisions were a characteristic of the older network environments that used hubs.
Broadcasts and Security
Broadcasting also has implications for how information moves around a LAN.
When a hub is used, communication between two devices can be seen by the other devices connected to that hub because the hub forwards the information to all of its ports.
Using a switch reduces much of this unnecessary traffic because the switch can direct communication toward the appropriate device. However, broadcasts can still occur on a switched network.
When a device sends a frame to the broadcast MAC address, the broadcast is sent to all devices within that local network.
Where Does a LAN End?
A LAN needs a boundary between the local network and the larger network beyond it. This is where a router comes into play.
The router represents the edge of the LAN. Within the LAN, we can have local communication, collisions in certain network configurations, and broadcast traffic. The broadcast traffic remains within that local network rather than continuing indefinitely into larger interconnected networks.
This separation is important because imagine if all network traffic, collisions, and broadcasts were allowed to spread across the entire internet. The amount of traffic generated by broadcasts alone would be enormous.
Instead, networks are compartmentalized and segmented, with routers providing boundaries between different networks.
Multiple LANs
A larger network can contain multiple LANs.
For example, one group of interconnected devices can form one LAN, while another group of devices forms a separate LAN. Routers can connect these different networks and route information between them.
This gives us a way to think about networks at different levels: individual devices can communicate within a LAN, while routers connect those local networks to larger networks.
LAN Protocols and Standards
The transcript also introduces the IEEE 802 standards, which include protocols associated with local area networking.
This is an important distinction because the concept of a LAN and the protocols used to implement LAN technologies aren’t always exactly the same thing. Technologies associated with the 802 standards can also be used in connections between networks.
The key takeaway is to understand the basic concept first: a LAN represents a local area network, while networking standards and protocols define how technologies within these networks communicate.
Why Broadcasts and LANs Matter
Broadcasts and LANs are foundational networking concepts that help explain how devices communicate and how networks are structured.
A broadcast allows a device to communicate with all devices on a local network. The broadcast MAC address identifies a frame as being intended for everyone on that network.
A LAN provides the local environment where devices communicate, while switches, hubs, and routers influence how that communication takes place and where the boundaries of the network exist.
Understanding these concepts gives you a stronger foundation for learning more advanced networking topics and building the networking knowledge needed for an IT career.
If you’re looking to strengthen your networking skills, check out the free Networking Starter Experience linked below. It can help you build the core networking foundation and confidence you’ll use throughout your IT career.
by Andrew Grimes | Sep 3, 2026 | ALL
https://youtu.be/wjf5j2NeWCc
When you connect a computer to a network, there’s more happening than simply plugging in a cable or connecting to Wi-Fi. Your device needs a way to communicate with the network, and the network needs a way to move those signals between devices.
Two important pieces of this process are the network interface card (NIC) and the network device that connects multiple computers together, such as an Ethernet hub.
What Is Network Media?
For devices to communicate, information has to travel from one device to another across some type of network media.
There are three basic ways we can send these signals:
- Electrical signals through a conductor such as copper cable
- Light signals through fiber optics
- Radio signals through the air
Regardless of the method, the goal is the same: transfer information between devices.
Computers work with 1s and 0s, so those bits have to be represented as signals that can travel across the chosen media. With copper, for example, an electrical signal can represent a 1 while the absence of a signal can represent a 0. Radio communication uses more complex methods to represent those same bits.
Fiber optics takes a different approach by sending information using light.
The Role of the Network Interface Card
Your network interface card, or NIC, provides the interface between your computer and the network.
Computers work with digital information, but the network media doesn’t necessarily communicate in the same form. A NIC helps translate the computer’s 1s and 0s into signals that can travel across the network media and then converts incoming signals back into information the computer can understand.
The term “network interface card” comes from the days when networking functionality was commonly provided by a separate expansion card installed into a computer.
Today, the NIC is often built directly into the motherboard or system.
A computer may have multiple network interfaces. For example, a laptop might have:
- Ethernet
- Wi-Fi
- Bluetooth
- Other network interfaces
In Windows, you can view these interfaces through Network Connections. You can also see information about an active connection, including its connection status, speed, and other details.
MAC Addresses and IP Addresses
When looking at a network interface’s details, you’ll encounter different types of addresses.
One of these is the MAC address, also called the physical address or burned-in address. The network interface has a MAC address associated with it.
You’ll also see an IP address, which is used for network communication at the IP level.
These addresses serve different purposes, and understanding the difference between MAC addresses and IP addresses becomes increasingly important as you learn more about networking.
Connecting Multiple Devices
Once devices have network interfaces, we need something that allows those devices to communicate with each other.
One example is an Ethernet hub.
A hub provides multiple ports where devices can connect using Ethernet cables. When a device sends a signal into the hub, the hub takes that signal and broadcasts it out through the other ports.
For example, if one computer sends a message into Port 1, the hub sends that signal out through the other connected ports. The other devices receive the signal and determine whether the communication is intended for them.
This is one of the fundamental ideas behind Ethernet communication.
Hubs vs. Modern Switches
It’s important to note that Ethernet hubs aren’t commonly used in modern networks. Switches are generally used instead.
However, understanding hubs provides a useful way to learn how Ethernet communication works. Hubs were part of the earlier development of Ethernet, and their simple behavior makes the underlying concept easier to visualize.
A hub essentially says: “I received a signal here, so I’ll send it everywhere else.”
A switch is more intelligent about how it handles traffic and can make forwarding decisions rather than simply broadcasting everything to every port.
Putting It All Together
The process of networking devices starts with the ability to physically or wirelessly transmit information.
Your computer’s NIC provides the interface between the device and the network media. That media might use electrical signals, light, or radio waves to carry information.
From there, networking equipment such as hubs or switches provides a way for multiple devices to communicate.
Understanding these foundational concepts makes it easier to understand everything that comes later in networking. Before you can learn about routing, subnetting, IP addressing, or more advanced networking concepts, it’s important to understand the basic question:
How does information actually get from one device to another?
Building that foundation is an important step toward developing the networking skills you’ll use throughout an IT career.
If you’re ready to strengthen your networking fundamentals, check out the free networking starter experience to practice these core concepts and build your confidence with computer networking.
by Andrew Grimes | Aug 27, 2026 | ALL
https://youtu.be/k0GVnwFNxWs
When we connect computers, phones, and other devices together, we need a way for those devices to communicate. But how does information actually travel from one device to another?
That’s where network media comes in.
Network media is the physical or wireless method used to transfer data between devices. At a basic level, there are three primary ways we can send information: electrical signals through a conductor, radio signals through the air, or light through a fiber.
The Three Ways We Can Send Data
Imagine that we have two computers that need to communicate with each other. Somehow, we need to get information from one computer to the other.
There are three basic options.
Copper Cable
The first option is to use a cable, typically a copper cable.
Copper is a conductor, which means we can move electrons through it. We can use changes in the electrical signal to represent the 1s and 0s that computers use to communicate.
For example, we can think of a signal being turned off as a 0 and turned on as a 1.
The actual technology used by networking equipment is much more sophisticated than simply turning electricity on and off, but this gives us a basic way to understand how information can travel through a copper cable.
Radio Signals
The second option is to use radio signals.
Instead of physically connecting the two devices with a cable, we can send information through the air using radio waves. Those waves can be manipulated to represent the 1s and 0s that make up our digital information.
This is one of the fundamental ideas behind wireless networking.
Your devices can communicate without a physical cable because information is being transmitted through the air.
Light
The third option is to use light.
We can send information by transmitting photons from one device to another. A simple example would be using a flashlight to communicate.
If we turned the light on and off in a specific pattern, we could create a code. Morse code is a simple example: short flashes represent dots, while longer flashes represent dashes.
Computers can use the same basic concept, except they can transmit signals far faster and use those signals to represent digital data.
This is the basic idea behind fiber-optic communication, where light travels through a fiber to carry information between devices.
How Do These Methods Represent Data?
Computers communicate using 1s and 0s, so network media needs some way to represent that digital information.
With a copper connection, electrical signals can represent the data.
With wireless networking, radio waves can be manipulated to represent the data.
With fiber optics, light is used to carry the data.
The underlying technology is different, but the goal is the same: move information from one device to another.
Why Does Network Media Matter?
Each type of network media has its own advantages and disadvantages.
Copper, radio, and fiber all provide different ways to move data, and the appropriate choice depends on the networking situation.
For now, the important thing to understand is that computers don’t simply send information from one device to another magically. There needs to be some form of media that carries the signal.
That media could carry electrons, radio signals, or photons.
Once you understand that basic concept, you have a foundation for understanding how devices actually communicate across a network.
Build Your Networking Skills
Understanding how data physically moves between devices is an important part of learning computer networking.
If you’re building your IT or cybersecurity career, having a strong networking foundation can make many of the concepts you’ll encounter later much easier to understand.
That’s why I created a free networking starter experience to help you build those foundational networking skills and gain confidence with the concepts you’ll use throughout your IT career.
If you’re ready to strengthen your networking skills, check out the free class linked below.
by Andrew Grimes | Aug 20, 2026 | ALL
https://youtu.be/Ao71PjFuXF0
When two computers communicate, they don’t necessarily run the same operating system, use the same hardware, or even look anything alike. One might be a Windows computer, another might be running Linux, and another could be a smartphone.
So how do all of these different devices know how to communicate with each other?
The answer is network protocols.
What Is a Network Protocol?
A network protocol is a set of rules for communication between devices.
Think about it like having a conversation with someone. For the conversation to work, both people need to understand the language being used and follow certain rules about how the conversation happens.
Computers work in much the same way.
When a device communicates with another device, the protocol helps determine things like:
- How communication begins
- What information is sent
- The format of the message
- The order information is exchanged
- How the receiving device should interpret the information
Without these rules, different devices and applications wouldn’t have a consistent way to communicate.
Why Do We Need Protocols?
Imagine you’re building an application that connects to a server.
The application might run on a Windows laptop, an iPhone, or an Android device. The server could be running Linux.
These devices and platforms can be very different from one another.
Yet the application still needs to communicate with the server.
The solution is to establish a common set of communication rules.
Protocols provide that common language.
Instead of every application developer having to invent an entirely new way for their application to communicate, they can use protocols that already exist.
Protocols Define the Order of Communication
One important job of a protocol is defining what happens and in what order.
For example, imagine an application that wants to retrieve a list of songs from a server.
The communication might follow a process like this:
- The client establishes communication with the server.
- The server responds.
- The client requests a list of songs.
- The server sends the requested information back.
The protocol establishes the rules for this exchange.
It can determine what message comes first, what response should follow, and what happens next.
Without those rules, the two devices wouldn’t necessarily know what to expect from each other.
Protocols Define Message Formats
Protocols also help define how information is formatted.
Imagine the server is sending information about a song. That information might include:
- Song name
- Artist
- Album
- Album artwork
- Lyrics
The receiving application needs to know what each piece of information represents and where it appears in the message.
If the information arrives in the wrong order or isn’t formatted correctly, the application could interpret the data incorrectly.
For example, the application might accidentally treat the album name as the song title.
Protocols establish the structure that prevents this kind of confusion.
Computers Are Really Sending Ones and Zeros
It’s also important to remember that the information being exchanged between computers ultimately comes down to binary data — ones and zeros.
The information might eventually be displayed to us as a nicely formatted application interface, but that’s not what is actually traveling across the network.
The data is transmitted and processed according to the rules established by the protocols.
Protocols provide the structure that allows those ones and zeros to become meaningful information.
We Don’t Have to Invent Our Own Protocols
If you’re developing an application that needs to communicate across a network, you don’t normally have to create your own protocol from scratch.
There are already many established protocols designed to handle different types of communication.
Applications and services can use these existing protocols rather than reinventing the rules themselves.
This is one of the reasons networking can work at such a massive scale.
There Are Layers of Protocols
Another important concept is that network communication doesn’t rely on just one protocol.
There are actually layers of protocols working together to make communication happen.
Different protocols can handle different parts of the communication process.
We’ll get into those layers in more detail as we continue learning about networking, but for now, the important thing to understand is that protocols provide the rules that allow devices and applications to communicate.
Why Network Protocols Matter
Protocols are one of the fundamental concepts behind computer networking.
Every time devices communicate across a network, there are rules governing how that communication happens.
Whether you’re accessing a website, using an application, transferring information, or communicating with another computer, protocols are helping make that communication possible.
Understanding protocols is an important foundation for anyone learning networking or pursuing a career in IT or cybersecurity.
If you’re building your networking fundamentals, start by understanding the basic concepts — because these fundamentals will continue to come up as you learn more advanced networking topics.
by Andrew Grimes | Aug 13, 2026 | ALL
https://youtu.be/cOTM7s6Gx1U
When you turn on your computer, hundreds of small programs may start running in the background. These programs provide much of the functionality your computer needs to operate, even though you may never directly interact with them.
If you’ve ever opened Task Manager in Windows, you’ve probably noticed a long list of processes running on your computer. Some of them may be familiar, while others might be programs you’ve never heard of. So how does Windows know which programs to launch, when to launch them, and how to keep them running?
This is where Windows services come in.
What Is a Windows Service?
A service is a program that can run in the background on a Windows computer without requiring a user to manually launch it.
Programs can be started at different points in time. Some launch when the computer starts. Others launch when a user logs in. Still others may start when you open a particular application.
The problem is that some programs need to run regardless of whether a particular user is logged into the computer.
For example, you may have a program that needs to be running as soon as the computer starts. You don’t want to wait for someone to log in and manually launch it.
That’s one of the purposes of services.
A program can be configured as a service so that it can start automatically and continue running in the background.
Services Can Start Automatically
Windows provides different startup options for services.
Some services can be configured to start automatically when the computer starts. Others can be started manually when they’re needed. There are also services that are configured to start automatically but with a delay.
This gives Windows flexibility in determining when programs should start and how they should operate.
You can see these settings directly on a Windows computer.
Open the Windows menu and search for Services. This opens the Windows Services console, where you’ll find a list of services configured on the machine.
The console provides information about each service, including its description, whether it is currently running, and its startup type.
Services Can Run Without You Launching Them
One of the interesting things about services is that many of them may already be running even though you haven’t opened them yourself.
You might see services running under different accounts, including local services, local system accounts, and network services.
This is important because these programs aren’t necessarily tied to the user sitting at the computer. They’re designed to provide functionality that the system or other programs may need.
That’s what makes services different from simply opening a program yourself.
Why Services Matter
Think about everything your computer needs to do in the background.
There are programs providing functionality to the operating system, programs supporting networking, and programs that need to be available even when nobody is actively using the computer.
If every one of those programs required a user to manually launch it, managing a computer would become extremely difficult.
Services provide a way to have those programs running in the background when they’re needed.
They help make sure that important functionality is available when the system needs it—not just when a user remembers to start a particular program.
What About Linux and UNIX?
Windows isn’t the only operating system that uses background services.
Linux and UNIX systems have similar functionality, although they use different terminology. The programs that are launched as services on Linux or UNIX systems are commonly referred to as daemons.
The terminology is different, but the basic idea is similar: programs can run in the background to provide functionality without requiring a user to manually launch them.
Seeing Services for Yourself
If you’re using Windows, take a look at the Services console on your own computer.
You’ll probably find a long list of services, many of which are already running. You can examine their descriptions and startup types to get a better idea of what’s happening behind the scenes.
The next time you open your computer and everything seems to simply work, remember that there’s a lot happening in the background. Services are one of the mechanisms Windows uses to keep those programs running and provide the functionality your computer depends on.
Understanding services is another important piece of building your foundational IT knowledge—because learning what’s happening behind the scenes helps you understand how computers actually work.
