What Is a Computer's Cache Memory?

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A cache is a specialized form of computer memory designed to speed up the user experience by making screens appear quickly without making the user wait for long.  The cache can be specific to a single software program, or it can be a small bit of hardware installed on your computer.

For most conversations around the Web and the Internet, "cache" is commonly used in the context of "browser cache". The browser cache is a slice of computer memory set aside to prioritize what text and pictures reach your screen when you click the 'back' button, or when you return to the same page the next day.

The cache holds copies of recently accessed data such as a web page and pictures on web pages. It keeps this data ready to "swap" onto your screen within fractions of a second. So, instead of requiring your computer to go to the original webpage and photos in Denmark, the cache simply offers you the latest copy from your own hard drive.

This caching-and-swapping speeds up page viewing because the next time you request that page, it is accessed from the cache on your computer instead of from the distant Web server.

The browser cache should be emptied periodically.