Both of these options will display exact decimal odds, alongside other odds. You can either choose the “Bet” option, which is shown in blue or you can choose the “Lay” option, which is in red. The way it works is that you will be faced with two options when placing a bet.
You won’t see these players, nor will you interact with them.
This means that you are not betting against the site, but rather you are betting against other players.
Well, it is that as well, but they are most known for their exchange. Betfair is a betting exchange, not a sports book.