They are different. A suburb is a residential community, not rural, just outside a city. A suburb usually describes a small town or city and is seldom considered a neighborhood. The outskirts of any area refers to the outer parts of that area - whether they are suburbs or not. Again, a neighborhood might be on the outskirts of a city, but "outskirts" used by itself would not refer to a neighborhood. A neighborhood loosely defines all the homes where people generally know each other. It usually defines a small area - smaller than a town. Surroundings usually refers to the physical area around a central area. It may or may not refer to a neighborhood, which is more of a social concept than one of area.