In most cases on modern operating systems (Windows or Mac) we rarely have to spare a thought for files extensions, those three (or more) letters at the end of a file name sometimes seen when you "Save As" a document.
File extensions indicate to the operating system the type of file a document is and then "File Associations" determine the correct application to open said file. Typically when a new application is installed that can handle a certain group of file types the user gets a chance to update file associations accordingly.
Sometimes file associations can become messed up or corrupt maybe through a bad software installation, when this happens photos may appear as garbled text documents or spread sheets my appear as corrupt .jpg images, this problem can be fixed by resetting your file associations to default settings.
Here are a few typical file extensions...
.doc - Microsoft Word Document
.xls - Microsoft Excel Document
.jpg - (.jpeg) Joint Photographic Experts Group - Photo or Image File
.gif - (pronounced "Jiff") Graphics Interchange Format - Image File
.png - (pronounced "Ping") Portable Network Graphics - Image File
.pdf - Portable Document Format - Typically Read Only Document
.mp3 - An Audio Coding Format - Music or Audio File
Have you got file association issues on your PC or Mac? The Computer Wiz can help, call 01553 660941 or email firstname.lastname@example.org