In Photoshop I have used many file types; psd, jpg, tiff, pdf, gif. TIFF - this is a tagged image file format, which is used for bit-mapped images.

JPEG – this is short for joint photographic experts group, it’s a lossy compression format for colour images. JPEG can usually reduce a file size to about 5% of its normal size.
GIF – this stands for graphics interchange format. It a bit-mapped graphics file format used by the Internet. GIF supports colour and various resolutions.
PDF – short for portable document format. This captures formatting information, and makes it possible to send a document as it was intended to be viewed. In the past it was only used by graphic artists and designers but today PDF and be used for virtually any data.
SWF – this stands for shockwave flash. It is a format for displaying animated vector graphics on the web.
HTML – this is a hyper text mark-up language, it is used to crate documents on the web. It is created using tags and codes. Starting with .
CSS – cascading style sheets, this is like html but the user has more control over how the pages are displayed.