How does asylum happen legally?

I'm curious. So I'm at Heathrow/Gatwick and approach immigration asking for asylum is that legal (I've got examples of people who have done this should you need them)?

What does the word asylum mean in your world? You ask for asylum then get flown to the other side of the world to what I would consider a questionable country(dictators going dictate) and are dropped off with the hope they're safer than they would have been were they to stay where they already were?