What is the purpose of the SSID, and what can a network administrator do to protect a network from hackers who might have learned the SSID?

What will be an ideal response?

The SSID is the name used to identify a network and is used by an access point
or a wireless router to establish an association so that a wireless client can join
the network. The SSID can be up to 32 characters and should be changed often
so hackers who have figured out the SSID no longer have access to the network