DEMO: Cookies and Caches

Cookies

Cookies and caches are both tools that can really help advance our experience when we're dealing with different websites and when we're dealing with our browser. It also can cause some problems, so it's important to know what they are and how to manage caches.

Let's first of all talk about cookies — and I'm getting hungry now. Cookies are a way that a website can store little pieces of information on your computer. Why would we want that? Well, for one, let's say I go to a site and I want to purchase something, and I load up my cart with all the things that I want to purchase, and then my browser crashes, or I get distracted and walk away, or my computer shuts off, or something happens. Then I go back to that site and I might lose all of the stuff that I researched and put in my cart that I want to purchase. What the browser can do, or this website can do, is store a little bit of information on your computer — information of what you've got in your shopping cart. That's great, because now when I go back to that site my shopping cart is already populated. Or let's say I'm logged into a site: maybe it automatically logs me into that site, or whatever information we want to store to make sure that we can gain access to that site and give us extra features and extra information to that browser, and pick up things where we left off. That little piece of information that gets saved is called a cookie.

For the most part, to a large degree, it's actually something that really serves us well. There are some downsides to these cookies, though. When you visit sites, they're reading information off of your computer, they're reading these cookies. One thing that can happen is that some of these programs can go in, or some of these sites can go in, and see where you've browsed in the past, and then start marketing towards you or using that information somehow. So there's both a pro and a con to these cookies when it comes to browsing different sites.

Caching

Another thing that can happen is caching. Caching is when we visit a site and files get stored on the computer, and there's some content that can be cached and some content that can't be cached.

Let me give you an example. Let's say I go to an online course and it has some videos, or it has some pictures that I am visiting. Those pictures might get stored locally onto your computer, so that way the next time I go to that site it doesn't have to redownload that information — it's already on my computer. Whereas if it's dynamic content, like maybe it's a report that I pull, then that can't really be cached on your local computer, because it needs to be up to date every time I visit that site.

If information does get cached on your local machine, usually there's some sort of expiration date on that, or expiration time, that once it gets to that expiration time it's got to redownload that file again, or maybe it just checks in to see, hey, is there an update to this file? So caching can really help speed up our accessing of these different sites by not downloading the same information over and over again.

When cookies and caches cause problems

Now, there is a downside to this. One of the downsides that we have is that if there's some information that does get cached, and then when we go and visit that site we're having some issues because of that cached information. So whether it's the cookies or cached information, it could be old information and needs to be updated. Maybe they've updated the site that we're trying to go to and our cache isn't updated, or maybe there's some sort of issue like that and we're not seeing exactly what we should be seeing. So sometimes we have to go in and clear our cache and our cookies in order to gain access to a site the way it's supposed to be presented to us.

Let me give you just a short little example of this. Maybe you have signed up for some online class, but then when you get into that class it's blank and it's not showing up. So you hit refresh on their web browser and it's not redownloading that information, and so something is a problem. You call up tech support, and one of the things they may ask you to do is to clear your browser history, clear your cache, clear your cookies, clear all of that, to make sure that you're getting the experience that you should be getting. A lot of times when you do that, you actually fix the issue, whatever issue that you're having. I don't see that as much of an issue as much anymore, but it certainly has been in the past, and it's certainly something that we still do when we're troubleshooting: clearing that history, clearing that cache, clearing the cookies.

Clearing them in the browser

I'm on my web browser here and I'm going to click on the settings. I'm going to get into the settings, and for Chrome it's under this privacy and security, so I'm going to click on privacy and security. As we see right here, we have delete browsing history, or delete browsing data, so I'm going to just go into that. It's not just the browsing data, it's cookies and other site data, and so this might be something that we want to delete or get rid of. And then same thing, cached images and files. So we can delete this data — if I delete it, then it will wipe that out. I'm not going to do this right now, but this is something that we could do to clean up files so that way we can make sure that we have some clean settings that we're working with.