No problem! I just had a quick search to find out more about this and read the following on
TasKiller Android App Review by AndroidTapp.com | Android Tapp. Android App Reviews -
"Most people who come to Android from a desktop environment find it a bit odd that you’re not required to shut down applications once you’ve finished using them. This is because Android terminates apps automatically when internal memory is getting low. Until that point they remain resident.
Sometimes though, it’s helpful to force close apps you’re not using to free memory, extend battery life and improve performance."