this is my first time using smartphone and i am currently using Samsung galaxy s2 running on android. I have downloaded apps such as Facebook, Hotmail, and couple games that i would use occasionally, but i have also downloaded the data usage watcher program called onavo and it keeps saying that live data are being used by these apps that i have downloaded and the ones that were already downloaded (Facebook, Hotmail, games, google services, and so on) its not a lot but why is it that they are using data when i am not actually on the app and using it at the moment?? and for my email it alerts me when ever there is a new mail, so does that mean that the apps are always connected? also,if i wanted the app that uses the data to stop using the data would i have to manually somehow disconnect it? and if so will it still work?
(sorry for the long and silly questions... its my first smartphone and i want to know all these basics..) thanks guys~

 

also... is there any way i can get rid of some of the preinstalled programs from the phone? like all share/ buddies now.. and is there any other program that i can use to see which application uses data? cuz i'm trying to get rid of the appl that i wouldn't need.. especially the ones that take up spaces and USES DATA WITHOUT EVEN ME KNOWING IT..