gzip is a software application used for file compression and decompression. It is a common way of compressing files in Linux.

The syntax gzip command
gzip [ -acdfhlLnNrtvV19 ] [-S suffix] [ name ... ]
On the man page the describes it
Gzip reduces the size of the named files using Lempel-Ziv coding (LZ77).
gzip command in Linux with Examples
Creating a compressed file
[huupv@DevopsRoles ~]$ gzip filename.txt
Decompress a File Using the gzip Command
[huupv@DevopsRoles ~]$ gzip -d filename.gz
The following details about gzip command in Linux.
man gzip
Conclusion
gzip command is a simple command in Linux. It is the most popular in use terminal Linux for file compression and