File Extensions

JPG is the most common file type, this file type is compressed and can be opened into most other applications. They are most often used on screen in websites and emails, this is in the most part because the files are quite small. These are not suitable for printing as they cant be edited an resized without loss to the image quality. A JPG is a raster file.

GIFS - Graphics interchange format. These files raster files, they are especially good for drawings/line arts. They are used in the same was as JPG file but are compressed even more, because of this they are not very good for photographs. Lossless format.

PNG - Portable network graphics. This file type has lossless compression, which means that images keep their quality and because of this, PNG is ideal for photos. They have larger file sizes and also doesn't store any additional info.

PSD is the file format that is mainly associated with photoshop, its images are of very high quality and the files are large. They stole lots of information with the image file, such as layers, masks and transparency.

TIF - A tagged image file has large file sized along  with high quality images, they can store information along with the image and usually uses a lossless compression format.

BMP - Bitmap, these files are the largest as they do not use any compression at all. They are only really used by microsoft/microsoft paint.