Complex sentence: The strong safety tends to be a bit larger and stronger than the free safety, however the word "strong" is used because he is tasked to handle the "strong side" of the offense, the side where the tight end lines up.
Split into simpler sentences: The strong safety tends to be a bit larger and stronger than the free safety. However, the word "strong" is used because he is tasked to handle the "strong side" of the offense, the side where the tight end lines up.