Created by Jean-Loup Gailly and Mark Adler., GZ is a software application used for file compression.
The file format GZ is based on the DEFLATE algorithm, which is a combination of LZ77 and Huffman coding. DEFLATE was intended as a replacement for LZW and other patent-encumbered data compression algorithms which, at the time, limited the usability of compress and other popular archives.
Although its file format also allows for multiple such streams to be concatenated (zipped files are simply decompressed concatenated as if they were originally one file), GZ is normally used to compress just single files. Compressed archives are typically created by assembling collections of files into a single tar archive, and then compressing that archive with GZ.