What Does Cache Mean?

Temporary files are stored in the cache to make things run more smoothly

A cache (pronounced cash) is a repository of temporary files that a device uses to speed up the user experience. There's a cache in a variety of places and on all sorts of devices. While every cache holds different information, they're all used for the same purpose.

Person clearing cached images on a computer
Lifewire / Theresa Chiechi

What the Cache Does

The cache makes it possible for a web browser to load recently accessed images quickly. Memory cache speeds up how screens appear on a computer. The cache in phone apps store relevant app information, and a router can hold onto data for quick access.

Without a cache, computers, phones, and other devices would not perform as quickly as they do now. However, the cache isn't always beneficial; it can consume lots of disk space, deliver corrupt files, and collect malware.

How Browser Cache Works

Most conversations that describe a cache deal with the browser cache. The browser cache is a slice of hard drive space that's set aside to gather commonly used items accessed through a web browser.

These frequency accessed files are stored so that the next time you need that data, the browser can open the files from the hard drive instead of downloading them from the internet.

For example, when you visit a website, the browser downloads images and text to your computer (or phone or tablet). If you reopen the same page two minutes later, those same files are still present on your computer. When the browser sees that the data you're requesting is available on your hard drive, it opens those files instead of downloading them again from the website's server.

The result is that the files are opened nearly immediately, saving you time. Less data is used, too, which is especially helpful for mobile users on limited data plans. Your phone doesn't have to download each image and web page repeatedly since it can restore the data from the cache.

Problems With the Cache

While benefits come with saving time and data, the cache can become corrupt and sometimes do more harm than good.

For example, a virus could download to the browser cache, infecting your computer. Files can become outdated if the cache doesn't purge itself automatically, meaning that the pages you see could be irrelevant or cause errors.

The cache is also fairly large and can take up gigabytes of data. Considering that some phones and computers have limited storage, caches of all types should be cleared as needed, including browser caches and app caches.

All web browsers have the option to clear the cache. This helps free up disk space, improve performance, remove corrupt files, and request new data from the web server.

You might clear the cache on your device, program, browser, or mobile app if it displays things oddly, operates slowly, crashes randomly, or behaves differently than it does generally.