You can open as many CFD contracts on a given underlying as you can afford buying into.
Each of them has the entry price achieved at the time you made the contract. If you have multiple contracts, it is likely they have all different entry prices. And for each of them you will probably exit them with a different exit price. Consequently each of them will produce a different result. So each one produces one such single difference.
Example from flat position buying three 3 CFDs at different times without closing any manually:

Time Product L/S Lots EntryPrice StopLoss TakeProfit
8:30 GER30 S 0.1 10728 10878
9:30 GER30 S 0.2 10722 10867 10700
10:30 GER30 S 0.2 10720 10870

At 15:30 with GER30 @10688 you will have two open contracts one with entry price 10728 and one with entry price 10720. Thus one is 40 points, the other 32 points in gain.
It helps the strategy to understand which contracts are open.