About every 3 years in the state of New Jersey (and on the national level via the NEC), the electrical code changes in some way. This may have an impact on you, your home, and any electrical jobs you may be considering.

For example, it used to be that you could use two conductors (“the black wire”) with a shared neutral (“the white wire”) and both circuits sharing that neutral would have independent circuit breakers. Through code revisions, now those 2 circuits must be on a 2 pole breaker …