Chmod

Chmod is a Unix/Linux command that changes file and directory permissions for owner, group, and others.

What is Chmod?

Chmod (change mode) is a command used to change the access permissions of files and directories in Unix-like operating systems, controlling read, write, and execute access.

Permission notation

Numeric (chmod 755), Symbolic (chmod u+x), Read=4, Write=2, Execute=1.

Common misconceptions

"777 is the solution" — Security risk, use minimal permissions
"Permissions are simple" — Context and inheritance matter
"Only files have permissions" — Directories too