Those are dialects. An accent is what you have as a second language speaker.

(Of course reality is more complicated; creoles and pidgins etc )

Is that true? I think a dialect needs to have at least some of its own words.

If people in your town use the same words as the town across the river, but you pronounce your R's and the others do not, I would say you speak the same dialect but with distinct accents.

Maybe the point is moot because any two populations separate enough to develop distinct ways of pronouncing words inevitably also create words of their own.

thats the thing, norfolk dialect had about four main strains, but most of the dialect as disappeared, leaving only the accent