Final answer:
Unix uses setuid and setgid to let users run programs with elevated privileges, which is particularly beneficial for tasks that require higher permissions than the user possesses.
Step-by-step explanation:
The mechanism provided by Unix through setuid (set user ID upon execution) and setgid (set group ID upon execution) is primarily for giving users the ability to run programs with temporarily elevated privileges, typically for the purpose of performing a specific task. When a program with the setuid bit set is executed, it operates with the owner's privileges rather than the privileges of the user running it. Similarly, a program with the setgid bit set runs with the group's privileges. This is useful when a program needs to access resources or perform operations that require different permissions than those of the user. For enhanced security, modern Unix-like systems may restrict the setuid/setgid behavior for scripts.