Who do the algos buy for?

So ok I heard the algos buy like today after Powell's speech.

So do they work for a company like Morgan Stanley or do they work for multiple companies?

Who controls them?

Like today after Powell's speech the news was good and so do they all “talk” to each other somehow and start buying?

Do all companies have algos?

Like Morgan Stanley, Goldman, etc?

By the way, what year did they start using algorithmic computers? 60s?