In my own words, the dwelling amount (or dwelling coverage or dwelling insurance) is the portion of insurance that covers the rebuilding of your home if it gets damaged by what insurance companies call a peril. If your agent uses the term “Coverage A”, they are still talking about the dwelling amount.
Examples of perils are fire, lightning, explosion, smoke, windstorm, hail, riot, civil commotion, aircraft, vehicles, vandalism, sprinkler leakage, sinkhole collapse, and volcanic action.
One thing to point out is that a peril is not the wear and tear of your home. You are responsible for your own home maintenance. For example, if your roof shingles start to “curl up” like eyelashes over time that is wear and tear and you responsible for that. On the other hand, if a rain and windstorm comes through your town and blows half of your shingles off the roof all at once, that would be a valid loss where we should notify your insurance company.