UMASK
UMASK, short for User Mask, is a command-line utility and shell setting in Unix-like operating systems, including Linux and macOS, used to define default file and directory permission masks for newly created files. Developed as part of the original Unix system in the 1970s, UMASK determines which permission bits are disabled when new files or directories are created.
CHMOD
CHMOD, short for Change Mode, is a command-line utility in Unix-like operating systems, including Linux and macOS, used to set file system permissions. It was developed as part of the original Unix system in the 1970s. CHMOD is used in terminal shells and scripts to control access to files and directories, specifying read, write, and execute permissions for the owner, group, and others.