what is the term which differentiate the Apple A7 and Apple A8 system on a chips?
Apple A8 The Apple A8 is a 64-bit ARM-based system on a chip (SoC) designed by Apple Inc. It first appeared in the iPhone 6 and iPhone 6 Plus, which were introduced on September 9, 2014. Apple states that it has 25% more CPU performance and 50% more graphics performance while drawing only 50% of the power of its predecessor, the Apple A7.
Pentalobe security screw The Pentalobe security screw (Apple nomenclature), or pentalobe screw drive, is a five-pointed tamper-resistant system primarily used by Apple in its products. Pentalobe screws have been used by Apple since 2009, when they were first implemented in the 15-inch MacBook Pro. They have since been used on other MacBook Pro, MacBook Air and iPhone models. Apple attracted criticism upon the introduction of the pentalobe screw; it was seen as an attempt to lock individuals out of their devices.