What Are File Extensions

Computer file extensions are suffixes that are added to the saved name of a file, usually 3 or 4 characters long. It is common in modern systems for these extensions to be hidden, but if you prefer you can often change the settings so that extensions are visible again.
You cannot open all files with all programs, so the purpose of file extensions is to identify what format the file is saved in, so that your operating system knows which program to use to open that file again. For example if your file is saved in .jpg, your system knows that is a image file, and that it needs to be opened with an appropriate imaging program, such as Microsoft Photo Editor.

One of the most common errors when opening files, occurs when your system operator cannot read the file extension correctly and therefore does not know what program to open it with. Sometimes you will be given the option of selecting a program from the available software yourself, but normally this error will occur when you do not have the correct software on your system in the first place, or the file has become corrupted. There are various websites, such as file-extension.com, that offer free scans that can help you identity why a file extension error has occurred, and also help you to resolve common problems.

There are hundreds of file extensions in existence, which cover a wide range of different computer formatting needs. The file extension M4A for example represents MPEG Audio files, and is a video streaming format which compresses video data for transmission. It is similar to MP3 file formats, but the overall audio quality is improved and .MP4A files are better at compressing data, making the final file size much smaller. It was developed by the Apple Corporation for use in their iTunes and QuickTime Player software, but can also be opened by the following programs; KSP Sound Player, Microsoft Windows Media Player and Roxio Easy Media Creator. If you do not have the appropriate program loaded onto your system, you will not be able to open .M4A files.

Another type of file extension is .TAR, which is mainly used on Unix systems. This file format combines with gzip software to compress and archive files and make them suitable for distribution. The main benefit of file extension TAR is that you can collate collections of files into one main larger file, whilst at the same time preserving all the vital file system information, such as date and directory structure.