A Handicap is a number of goals or points that is given as a head start to a team, or as a negative score to overcome for betting purposes.
The favorite team or player in an event would have a handicap that theoretically makes them start at a negative score, and must win the match from this point to make the bets on the handicap win.
The Underdog of an event would have a handicap that gives that team or player a head start, where they start with a score already registered for betting purposes, and must either win the game normally, or not lose by a score that overtakes the handicap given.
Handicaps markets are listed with various options of advantages or disadvantages applied, with 1:0 meaning the home side gets a 1 goal start, 0,2 gives the away side a 2 goal start and so on.
For other sports, the handicap may show 3 fields, such as 0:1,5 or 2,5:0. This is for different handicaps where there is no option to bet on a draw and this is because there is a "half" point or goal applied so that after a handicap is applied, the scores cannot be tied.
0:1:5 is the away side with a 1,5 point start, 2,5:0 is the home side with a 2.5 point start.