Final answer:
The two commands to enable and disable an interface on a switch are 'no shutdown' and 'shutdown'. If you make a mistake while editing the configuration file and haven't saved it, you can use the 'reload' command to reboot the switch.
Step-by-step explanation:
The two commands to enable and disable an interface on a switch are no shutdown and shutdown.
To enable an interface, you can use the no shutdown command. This command removes the shutdown configuration and enables the interface to function. Example: no shutdown
To disable an interface, you can use the shutdown command. This command puts the interface into a shutdown state and stops the traffic flow. Example: shutdown
If you make a mistake while editing the configuration file and haven't saved the configuration, you can reboot the switch to discard the changes. The command to reboot a switch is reload. Example: reload