A file extension enables your computer to identify a particular document or file and open it in the appropriate program.

The extensions are easy to spot as they are the letters following the dot (full stop) after the file name.

For example: Photoshop files are 'filename.PSD', Word documents are 'filename.doc' and JPEG images are 'filename.jpg'

Sometimes we need to know just what format a particular file format / file extension is - This can be out of curiosity or because we need to know how to open the file. There are hundreds of file formats. Here's a useful link for amny file formats: http://en.wikipedia.org/wiki/List_of_file_formats

For Digital Photography, this link may be useful: http://www.scantips.com/basics09.html

The link below will open my webpage about File Formats for Digital Imaging