“The terms accent and dialect are almost interchangeable; in popular parlance they mean much the same thing. But some distinctions may be useful. In its scholarly sense, a dialect is a legitimate variant of a language, telling us about the regional and caste/class origins of the speaker and more. We refer to the Lancashire dialect of English, or the Parisian dialect of French. A dialect has its own vocabulary and grammar, as well as its own distinctive pronunciation. We are all dialect speakers, then, even if we happen to use the prestigious “standard” dialect of our own language. For it, too, is a dialect. An accent, on the other hand, is simply a feature or attribute of a dialect or language, referring to its pronunciation.”
from
“Dialects of the British Isles”
by Paul Meier