First of all, Spread Betting is a whole other ball game... (I believe it's what you call Action Points on your side of the pond) What you're asking about is called Asian Handicap Betting. Pretty much what Joey said, but copied from Pinnacle's help section:
Handicap Betting: Soccer games may have either a Single Handicap or a Double Handicap.
Single Handicap: This bet type is similar to a bet on the spread in basketball.
For example:
Arsenal -1, -125
Newcastle +1, +113
If Arsenal wins the match by two goals or more, Arsenal bettors win and Newcastle bettors lose. If the match is drawn or if Newcastle wins, Newcastle bettors win and Arsenal bettors lose. If Arsenal wins by exactly one goal, all bettors receive a refund.
Double Handicap: This bet type splits a wager into two bets, each with the same moneyline, but at a different single handicap.
For example:
Real Madrid -1 and -1.5, -108
Barcelona +1 and +1.5, +100
A client who bets $100 on Real Madrid actually has two separate bets on Real Madrid: $50 on Real Madrid -1 at -108 and $50 on Real Madrid -1.5 at -108.
A client who bets $50 on Barcelona actually has two separate bets on Barcelona: $25 on Barcelona +1 at +100 and $25 on Barcelona +1.5 at +100.