setuid short for set user ID upon execution is Unix access rights flag that allow users to run an executable with the permissions of the executable's owner. This is often used to allow users on a COMPUTER system to run programs with temporarily ELEVATED privileges in order to perform a SPECIFIC task. While the assumed user id privileges provided are not always elevated, at a minimum that is specific. 

setuid and setgid are needed for tasks that require higher privileges than those which a common user has, such as changing his or her login password. Some of the tasks that require elevated privileges MAY not immediately be OBVIOUS, though - such as the ping command, which must send and listen for control packets on a network interface.

setuid short for set user ID upon execution is Unix access rights flag that allow users to run an executable with the permissions of the executable's owner. This is often used to allow users on a computer system to run programs with temporarily elevated privileges in order to perform a specific task. While the assumed user id privileges provided are not always elevated, at a minimum that is specific. 

setuid and setgid are needed for tasks that require higher privileges than those which a common user has, such as changing his or her login password. Some of the tasks that require elevated privileges may not immediately be obvious, though - such as the ping command, which must send and listen for control packets on a network interface.