You can give someone permission to run only certain commands with sudo, but that can be dangerous in non-obvious ways.

As a slightly contrived example, imagine you allow someone to use "apt-get update" with sudo, reasoning that it only changes a local index and doesn't alter the system. You don't allow them to use sudo for anything else.

If they run "sudo apt-get update -o APT::Update::Pre-Invoke::=/bin/sh" they get a shell that lets them execute any command as root, not just the command you gave them permission for.