What is the difference between a Pentalobe screwdriver and a Phillips screwdriver?

I'm asking this question with particular regards to replacing the front and back panels of an iPhone 4 or 4s.

I understand that the Pentalobe screwdriver has been implemented by Apple with its products but I'm not sure whether a Phillips screwdriver is also needed. Particularly in regards to replacing a front LCD plate.

A pentalobe screwdriver has 5 points whereas a Phillips screwdriver has a cross-head (4 points).

Don't know anything about iPhone front plates I'm afraid but this site may help…

http://www.imobiledoctor.com/iPhone-4-Pentalobe-Screwdriver-s/120.htm

They were not the same shape and they can't be interchangeable. Pentalobe screw types were widely used in aviation instrument long long time ago. Its proper name called Bristol screw. Car also used large size Bristol screw. Screw driver or allen key for it was quite expensive and hard to find the supplier in the old day. See this image…

http://www.google.ca/...0QHE7YHoBQ