Preview lessons, content and tests

Computer Science & Programming solved. All in one platform.

1. To trial the platform and take tests, please take a few seconds to SIGN UP and SET UP FREE.
2. Searching for something specific? See our text overview of all tests. Includes 'real teacher' use videos.


Processing power and storage space is very valuable on a computer. To get the best out of both, it can mean that we need to reduce the file size of text, image and audio data in order to transfer it more quickly and so that it takes up less storage space. In addition, large files take a lot longer to download or upload which leads to web pages, songs and videos that take longer to load and play when using the internet.

Compression addresses these issues. Any kind of data can be compressed. There are two main types of compression: lossy and lossless.

Suggested Videos

Mr Brown Computer Science: Lossy and Lossless (RLE) Compression