umask stands for ‘User file creation mask’, which determines the settings of a mask that controls which file permissions are set for files and directories when they are created. While ulimit is a linux built in command which provides control over the resources available to the shell and/or to processes started by it.
You can limit user to specific range by editing /etc/security/limits.conf at the same time system wide settings can be updated in /etc/sysctl.conf
