Desktop: by selecting either fractional or decimal from the black banner at the bottom of the page. Mobile: by clicking on your balance and selecting 'Settings' and 'Odds Display'.

Fractional odds represent the profit - 5/1 means you will win five pounds for every one pound staked - whereas decimal odds represent the return - 2.2 means you will receive 2.20 for every 1 invested, including your stake. So, think of decimal odds in monetary terms.

Donk is a (potentially offensive) term used to describe a very bad poker player. A donk bet is a bet made out of position after check/calling on the previous street. The link here is that it's usually 'donks' who donk bet hence the name behind the bet.

An up-and-down bet involves two selections and two separate bets on both those selections, in each of which the second bet is conditional on the first one winning.