Setting and atmosphere can be used explicitly or implicitly. The latter is a little difficult to do and requires skill.
Nevertheless, if written properly, you should create a vivid picture in the readers mind so that they feel as if there are in that place, or at least they should be able to relate to it if your writing is convincing.
Tip: Balance ‘telling’ with ‘showing.’
Setting and atmosphere are vital components when writing fiction, though it works quite well in non-fiction too. Just read ‘The Pursuit to Happyness’ by Chris Gardner.