The ".7z" file extension denotes a compressed archive format created by the 7-Zip software. This format is known for its high compression ratio, which allows users to reduce the size of files and folders for easier storage and sharing. It supports various compression algorithms, making it versatile for different types of data. Files in the ".7z" format can contain multiple files and directories, similar to other archive formats like ZIP or RAR. To access the contents of a .7z file, users typically need to use compatible software, such as 7-Zip or other archive managers that support this format.