For example, with an image file, the image's colour depth and pixel resolution will decrease, so it may look worse but more of these files can be stored in the same space.
Try using the slider below, which will try to simulate colour depth and resolution!
One of these is audio files, like .mp3. This can be done by reducing the sample rate (no. of samples taken per second), or the bit depth (no. of bits used to record each sample).
With large amounts of compression, the file will sound much worse, but can reduce the storage space required significantly
