Audio/Video Controls ?

I’m trying to find equipment to feed multiple TV monitors in school classrooms with a common feed, such as announcements or videos, and possible also control a few remote video cameras for hall monitoring, ect…Have the sound system handled.
Anyone know where to start searching for hardware on the internet, such as key words to enter for searching ? I know " video controls " won’t get you anything but a lot of useless sites.
Any suggestions ?
Thanks,Bubinski.

You can start by looking for “video distribution amplifiers”. These will allow you to split a video sgnal and feed it to multiple receivers. And “closed circuit video monitoring” or “video surveillance system” should get you what you need for the cameras.