Well i found this online:
Abhidhamma And Practice
By Nina van Gorkom
Citta is the first of the four types of paramattha dhammas. It is also the fifth group of aggregates. The word ‘citta’ is derived from the root ‘cit’, to think. Citta is that which is the chief in experiencing an object. There are many different types of citta. They are divided four ways according to whether it is –
1. consciousness pertaining to the sense sphere (kamavacara citta),
2. consciousness pertaining to the form sphere (rupavacara citta),
3. consciousness pertaining to the formless sphere (arupavacara citta),
4. supramundane consciousness (lokuttara citta).
The four categories of consciousness are classified according to whether they are wholesome or skillful (kusala citta), unwholesome or unskilful (akusala citta), the result of deeds (kamma) in the past (vipaka citta) or neutral consciousness with on effect (kiriya citta). http://www.dhammastudy.com/abhid-pract.html
So i guess that explains that.