The FAA defines 3 categories for small airplanes:

Normal: all standard private and commercial flight maneuvers up to 60* bank angle. Must withstand 3.8 G or more.

Utility: additional flight maneuvers like spins and > 60* bank angles. Must withstand 4.4 G or more.

Acrobatic: any maneuver or bank angle not prohibited by the POH. Must withstand 6.0 G or more.

All certified GA airplanes meet the Normal category, many (like the Cessna 172) meet the Utility category, and some meet Acrobatic. With 3.8 G as the minimum, this means airplanes are built very strong.

You don’t really know how strong the airframe is because the G rating is a minimum. It can handle that G load under normal operation. Certainly it can handle more, but how much more is unknown. If you exceed it, you’re the test pilot – that’s bad, don’t do that.

Being certified Utility doesn’t necessarily mean the airplane can perform any maneuver exceeding 60* of bank. For example many aircraft certified Utility are not approved for spins. Prohibitions like this are listed in the POH.

Airplanes certified for multiple categories may not always satisfy all categories. For example the Cessna 172 is certified Utility only when gross weight is under 2,100 lbs. and CG is forward of a certain point. Otherwise, it’s certified Normal.