File formats
and compression

index > 2.1.6 Computer communications and networking

File formats

Here are the main file formats you need to know:

Standard Definition Uses
JPG or JPEG Joint Photographic Experts Group Stores images with lossy compression.
GIF Graphic Interchange Format Stores bitmapped images using lossless compression.
PDF Portable Document Format Shows documents the same way with any software that opens them.
MP3 Moving Picture Experts Group Audio Layer III Digital audio using lossy compression.
MPEG Moving Picture Experts Group Represents videos using lossy compression.


Compression is used to reduce the size of files. This is done to save storage space on portable devices and to reduce transmission and download times on networks like the internet. The disadvantage of compression is that they need to be decompressed which slows operation times.

There are 2 main types of compression: