what do fire lookouts look like, and how do they coordinate with firefighters?

Don't live in a country where fire watches are common and I heard about them just now, and can't find detailed answers online. Are the people on fire watches firefighters too? If not, do they just phone the firefighters and go "hey, there's a fire at x location"? I'd assume they take shifts, but how long would those shifts be? Are there any criteria they have to meet (like being a certain age, or some kind of test). How would they have done this back in, say, the 80's? Has anything significantly changed so far? I suppose this is a lot, but thank you for any responses! very curious and would like to know more:)