What type of skin disorder is eczema

Eczema is a term of group where your skin will get irritated and itchy. Atopic dermatitis is a common group. I'm not sure this answers your question or what but this is some information that I know

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it