In Phoenix it generally will or will not cover water trash and sewer. If it is a town home or condo it usually will cover at least trash and sewer but not always water. The trash and sewer part of the water bill is usually half of a normal water bill for a single family. It usually covers common areas. If there is a common area pool it will will cover pool maintenance and repair. If it is a connected building style it can include outside maintenance of the unit and front yard maintenance street upkeep, gates, roofs, basic insurance of common area and the structure. This really can be a very general question I hope I gave you some idea of what and how complicated this question is.
These vary from association to association. Usually common areas maintenance, exterior maintenance sometimes, this is really why you get five days to review the hoa rules and regulations, but your buyers agent can call the specific asociation and find out specifics.
Generally trash, snow, common area maintenance, some also include exterior maintenance on buildings, usually with a higher monthly fee. It should state it on the MLS info page you receive from your Realtor.