SU (superuser)
SU is the switch user, such as: input: Su command after the return of the current user to switch to the root user, or: input: su-root (or other user name) here added "-" after the change of the current environment variable to the new user's environment variable.
Su Root (or another user name) indicates that the environment variable is not switched to the current user.
sudo means to get the temporary root command, such as Sudo gedit/etc/shadow, which means to temporarily use root permissions to edit the/etc/shadow password file because the/etc/shadow password file requires root permission to open and edit. This is why the sudo command is used to temporarily use root permissions to do some work that cannot be done on a regular account.
Sudo-i is logged in as root, the actual user ID and valid user ID of the process become root, and the home directory is switched to the root directory.
To get root privileges:
1, sudo su (essentially Su, and Su by default is to get root permissions)
2, Su
3. Su Root
4, Su-root
5, Sudo-i
The difference between the Linux su and sudo commands, and get root permissions