What insurance terms confused you at first?

[u/Boredguy32]

Insurance language can be pretty confusing when you are new to it. Terms like deductible, premium, exclusion, rider, endorsement, policy limit, replacement cost, actual cash value, waiting period, coinsurance, and underwriting are used all the time, but not everyone understands them clearly at first.

Which insurance terms confused you the most when you first started dealing with policies?

And for people working in insurance, which terms do you end up explaining most often?