HDBaseT is like a super-duper long cord that can carry lots of different things, like video and audio signals, from one place to another.
Imagine you have a TV and a DVD player in your living room, but you want to watch a movie in your bedroom. Normally, you would have to unplug everything and move it all to your bedroom, but with HDBaseT you don't have to do that! You can just plug one end of the HDBaseT cord into your TV and the other end into your DVD player, and then plug another HDBaseT cord into your bedroom TV and the other end into your living room DVD player.
The HDBaseT cord is able to send all of the video and audio signals from your DVD player to your bedroom TV, so you can watch your movie without having to move anything. Plus, the HDBaseT cord can carry other things too, like Internet signals, so you can even access the Internet on your bedroom TV.
So, HDBaseT is like a magic cord that lets you transfer all kinds of things from one device to another, without having to unplug and move everything around.