How TV channels works ?

Sorry, i did post this question on Quora but didn't get any answers ans so as Reddit, so my questions is do TV channels buy some kinda hosting like websites do or something like that ? how they broadcast their tv shows/programs and shit ? thanks guys

Google "how do tv channels work"

There some signal over the air and other that probably need kind of server for the hosting.
Why do you wanna know that ? It's the making money section ..