( USA) A homeowner's association (HOA) is an organization in a subdivision, planned community, or condominium building that makes and enforces rules for the properties and residents.
HOAs make rules on, among other things, what color you can and cannot paint your house, how long you can let your grass go before mowing it, If you have a boat or RV where you can keep your boat or RV, type of fence you can have around your house, flag poles, TV antennas, satellite dishes, and other such rules that affect the visual appearance of the neighborhood (real estate development). They also collect dues for the maintenance of common areas such as retention ponds, community swimming pools, playgrounds, etc. if they are part of the development. This is in the interest of preserving general curb appeal of homes in the development which means home owners maintaining the property value of their home. Why is this important? because if "you" are going to get a 30 year mortgage on a home for, say $150,000 (at whatever interest rate) and put $30,000 of your own cash into it as down payment, you don't want to owe more on the house than it's worth (be upside down on a loan) should you have to sell your house anytime in the near future.