in typin on a keyboard wen u learn professional typin, it is taught dat u need to keep ur left index finger on d letter f n d rite index finger on d letter j wid ur thumb on d spacebar. to demarcate it dey hav d dot/dash on d keyboard

similarly on d phone u hav a dot on d number 5 so u can keep ur thumb in dat position n it wil b easiest to naviagate wen punchin d odr numbers

coolllll .  . didnt know dat . .. thks mehwish

That little dot tell people that are blind that is the #5 key. They know what direction to go from there to get to the other numbers they want. You find that on most of the phones and calculators. There is a dot on the letter "F" and the letter "J" on computer keyboards. Your left index finger goes on the F key and your right one goes on the J key. On key boards it is for people that can see as well as those that can't.