su and sudo command

Switching User command : su su command format : su [options] [username]

Executing Privileged Commands : sudo sudo command format : sudo [options] command

Command Example Explanation
su - Switches to another user account, usually root.
- Starts a new shell.
- Requires the target user’s password.
su alice - Switches to user “alice”( Requires alice’s password).
sudo - Runs a single command with superuser (root) privileges.
- Does not switch users.
- Requires your own password, if allowed in /etc/sudoers.
sudo apt update - Runs the apt update command with root privileges.

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Quick comparison:

  • su = switch user → full login as that user.
  • sudo = superuser do → temporarily run commands as root.
  • su starts a new shell; sudo runs one command at a time.