What is a cache?

What is a cache and what happens when they are cleared? In this blog post, you can read about caches and what they mean for your devices.

29-08-2022 - 7 minute read. Posted in: cybercrime.

What is a cache?

If you've ever bothered to troubleshoot your computer or clean up your browsing history, you've probably read somewhere that you should "clear the cache".

So what exactly is a cache and what happens if you clear it? In this blog post, you can read everything there is to know about caches and the impact they have on your digital life.

What does "cache" mean?

A cache is a reserved storage location that collects temporary files and data to make websites, browsers and apps load faster. Whether you're on a computer, mobile or tablet, or in a web browser or app, they contain a variety of caches.

A cache makes it quick and easy to download data, which further helps digital devices run faster. A cache is used as a memory bank, making it easy for you to access data locally on a website or in an app, rather than having to download it again every time you visit the website or app.

There are three main areas where caches have an important role in digital devices:

Your devices and software

You can find caches in both hardware and software. The CPU (cf. central processing unit) is the core component responsible for processing information from the software on your computer, smartphone or tablet, and it has its own cache.

A CPU cache is a small block of memory designed to help the CPU download information that is frequently used. If your device only had to load each piece of information when it was requested, your device's main memory would spend much longer retrieving the data it needs to execute instructions. And your device, such as your computer, would run much more slowly.

You can furthermore consider which best practices you should adopt to secure your device and systems - in this case, clearing caches is a great way to start.

Your web browser

Every web browser, whether it's Google Chrome, Microsoft Edge, Firefox or Safari, maintains its own cache.

A browser cache stores all the data your browser needs to show you the websites you visit. This includes elements like the HTML file that describes the website, CSS type sheets, Javascripts, cookies and images.

If you, e.g., visit eBay, the browser cache downloads all the images embedded in the product pages you visit, the HTML and other script files needed to display the pages, and personal information such as your login details and the products in your shopping basket.

If you clear your browser cache, retail websites will ask you to log in to your account again, as all the information mentioned above has been deleted.

Your apps

Apps usually maintain their own cache as well. Like web browsers, apps store files and data that help them quickly reload information as needed. However, each app is different, so the type of data stored in the cache will vary, but it's typically images, thumbnails, search history and other user preferences.

What are the benefits of caches?

From a user perspective, there are three primary benefits of caches:

  • They make your digital devices run faster. The most important benefit of all caches is that they improve system performance. For example, by storing local copies of files from websites, your browser only needs to download the information the first time you access the website, and it can then just load the local files. This allows the website to load faster.

  • They store data. To improve performance, apps cache new and frequently used data. This means both that the app can run faster and that in some cases it can work "offline". An example might be that you don't have internet access. In some cases, an app can use the cached data to continue functioning even without a connection.

  • They store data for later use. It is quite efficient to download files or data only once. If a copy of a file is stored in a cache, an app doesn't have to waste time, battery power and other resources downloading it every time you open the app. Instead, the app only needs to download new files/data, and files/data that have been modified.

Cashes make the user experience a lot better and more smooth, since we don't need to enter our details at every log-in. There can, however, be some points for concern.

What are the disadvantages of caches?

While modern software relies heavily on caches, they also have some drawbacks:

  • They can take up a lot of storage space. Simply put, a cache is a small storage of files used by an app, browser or other device. But some caches can contain large amounts of data and limit the available space on your device. Clearing the cache can delete the files and make room for a large amount of memory.

  • A damaged cache can cause an app or browser to run poorly. If something is wrong with a file stored in the cache, it can cause the app or browser to display data incorrectly, show errors or even crash. That's why a common solution - if you're having problems with your browser - is to clear the cache.

  • Caches can prevent apps or browsers from loading the latest version of a website or other data. In principle, apps are only supposed to use the cache to display files or data that have not changed since the last visit.

However, this doesn't always work and sometimes the only way to see the latest version of a website or other information is to clear the cache, forcing the app or browser to download everything again.

What happens when you start clearing the cache?

Although there are some drawbacks to caches, it makes good sense to clear your cache as part of regular maintenance of your systems. In addition to the risk of corrupt files if a cache gets too large or if your computer starts to run out of storage space, these problems can also affect your computer's performance.

The solution is to "clear the cache", which deletes the temporary data stored in the cache.

If it's possible to clear cached data as a user, the program that owns the cache generally makes that option available somewhere in the program's settings menu.

The benefits of clearing a cache are that it frees up previous storage space on your computer, and it eliminates any files that can cause your computer to run poorly or slowly.

However, clearing the cache can also mean deleting files that are designed to make your computer run more efficiently. For instance, clearing a browser cache typically means you'll have to log in to all your frequently visited websites again, and you'll lose any special customisations or personalisations you had there, including the contents of shopping carts.

But if you're experiencing problems with your digital devices, it's worth clearing the cache. It is also worth mentioning that it is good cyber hygiene and cybersecurity to clear all cache once in a while, as the stored data can be exploited by cyber criminals.

Clear cache in Google Chrome

Clearing your cache in Google Chrome is easy and it doesn't take very long. It can be done on both desktop and mobile, and it's basically the same procedure.

You need to do the following:

  1. Open your Google Chrome. Click the "More" icon (it looks like three dots) at the top right of your screen.

  2. Select the "More tools" checkbox and then "Clear browsing data" from the drop-down menu.

  3. Select a time interval in the pop-up menu. Options range from the last hour to all the time you have used your computer's browser.

  4. Make sure the boxes next to "Cookies" and other site data and "Cached images" and files are checked.

  5. Click on "Clear data".

Now the cache is cleared and your device is better suited against the cyber threat. Online behavior is essentiel when it comes to cyber hygiene, and you are now well on your way to achieving that.

This post has been updated on 24-07-2023 by Sofie Meyer.

Author Sofie Meyer

Sofie Meyer

Sofie Meyer is a copywriter and phishing aficionado here at Moxso. She has a master´s degree in Danish and a great interest in cybercrime, which resulted in a master thesis project on phishing.

View all posts by Sofie Meyer

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