Owning property gives you certain rights, including the right to decide who gets to use your land and for what.  Before you purchase real estate, you should understand the difference between an EASEMENT and an ENCROACHMENT.  The latter is a violation of your rights, while the former is an exception to them. 

EASEMENTS:
An easement is a right that others have to use property belonging to you.  For example, a utility company's right to access a property for maintenance, or a neighbor's right to cross a property to get to a public road.  Existing easements typically carry over when a property changes hands.  For this reason, it is important to inspect the documents prior to purchasing property to see if there are any easements on it. 

ENCROACHMENTS:
Encroachment occurs when someone else makes use of your property without an easement. Whether by mistake or intentional act, an encroaching structure is one that is on your property without your consent.  Even if an encroachment doesn't bother you, it can create headaches in ensuring a clear title for purpose of title insurance, and it can even impact your homeowner's insurance policy if someone is injured on or by an encroaching item.