man pages are your friend. Whenever you see a command you've never used, run
man [name of command]
man sudo will tell you:
sudo, sudoedit - execute a command as another user
and, lower down:
sudo allows a permitted user to execute a command as the superuser or another user, as specified in the sudoers file. The real and effective uid and gid are set to
match those of the target user as specified in the passwd file and the group vector is initialized based on the group file (unless the -P option was specified). If
the invoking user is root or if the target user is the same as the invoking user, no password is required. Otherwise, sudo requires that users authenticate
themselves with a password by default (NOTE: in the default configuration this is the user's password, not the root password). Once a user has been authenticated, a
time stamp is updated and the user may then use sudo without a password for a short period of time (5 minutes unless overridden in sudoers).
If the wording is too complicated, that's when you do a Google search such as "Linux what does sudo do?"