My friend isn't exactly a comp expert. So when he installed his webcam, it didn't work and so he asked his friend for his driver (logitech). So his friend sent it to him and it works on his cam too? I know that his cam isn't logitech it's something else. So I am wondering would it hinder the webcam's performance or shelf life?

If a driver for another product worked, it is only a coincidence. If it does work, it's is really up in the air as to whether or not it will end up causing problems. If the coding of the actual driver is very simialr to the one that is intended for the hardware, you may never have a problem. On the other hand, the driver may be similar to required driver but not close enough to run perfectly. If this is the case, the driver will probably work ok for most normal tasks but might fail when trying to complete certain complex tasks.

The bottom line is, there is no way to tell how a driver designed for different hardware will function well but usually any problems will be limited to the hardware run by that specific browser.

Could be the cam just happened to be made by the same company as Logitech