Remote control fobs are a wireless/radio transmitter remote where you are able to control your applications with a push of a button by connecting to the receiver relays. These remotes can have up to 8 buttons/channels that you can operate with and have a variety of ranges allowing you to use these remotes from distances.
You can have wireless, Bluetooth or radio transmitter remote control systems. Once you have connected the remote control fob to these connection/receiver then your remote will work with whatever functions you need for your application.
For example - a two button remote control fob can be used with electric gates when you are in range of the receiver and can simply work with an 'Open' and 'Close' button.
Remote control fobs can be used for a variety of applications such as:-
Wireless lighting controls
Roller shutter doors
IOT (Internet of things)