Why students bring cellphones to school?

we children like to use cell phones alot because it makes us have something to do and we can talk to our friends. so example say sally wanted to hang out with her friend but didnt have anyway to get in touch with her instead of driving all the way to the house and find out sallys friend cant hang out it would be a waist of gas so if she just had her cell phone she could txt her friend or call her friend to see if she can hang out