Question

what part of computer that provides internet access

Answer 1

It is the router i have to put hella words and alla dat but itz tha router

Answer 2

If you’re talking about the computer itself, it can be one of three things.

1) An internal wireless piece (one inserted on the motherboard
2) Am external wireless piece (a usb stick that provides wireless internet)
3) An ethernet cable plugged into the back of your computer

If you want the strongest connection, use an ethernet cable.

Also I recommend to not use wifi extenders, they suck.