p7zip is the Unix port of 7-zip, the open source file archiver that archives with a very high compression ratio. p7zip provides 7z with LZMA high-compression format and 7za.
By default Ubuntu can’t create or extract 7z files, so to extract archives compressed with the 7-Zip format, you’ll have to install 7z file archive support from the package p7zip (click the link to install), via Software Center or by running the sudo apt-get install p7zip in your terminal.
To quickly create 7z archives, right-click on the file or folder and select ‘Compress’, then choose the .7z format. Extract 7z archives by right-clicking on the archive and ‘Extract Here’.