Here is the video version, if you prefer it:
In shell scripts, one-line comments start with a #. Comments are ignored by the interpreter, but they serve to instruct the human reading the script on what should the script do.
There also exist multi-line comments; see (“Shell Comments,” n.d.).
Thank you for reading!
References
Shell Comments. (n.d.). Retrieved March 7, 2020, from https://bash.cyberciti.biz/guide/Shell_Comments