A file extension (or simply “extension”) is the suffix at the end of a filename that indicates what type of file it is. The term actually stands for “Joint Photographic Experts Group,” because that is the name of the committee that developed the format. For example, in the filename “myreport.txt,” the .TXT is the file extension. It indicates the file is a text document. Some other examples include .DOCX, which is used for Microsoft Word documents, and .PSD, which is the standard file extension for Photoshop documents.
.JPEG File Extension:Compressed image format standardized by the Joint Photographic Experts Group (JPEG); commonly used for storing digital photos since the format supports up to 24-bit color; therefore, most digital cameras save images as JPG files by default.
File Format Description: JPEG is also a common format for publishing Web graphics since the JPEG compression algorithm significantly reduces the file size of images. However, the lossy compression used by JPEG may noticeably reduce the image quality if high amounts of compression are used.