Mechanic's liens provide contractors and subcontractors with a means of collecting payment for construction work and supplies. The lien allows you to eventually take possession of property upon which you completed work for which you were not paid.
Seller financing occurs when a seller helps to finance a real estate sale. It is usually used when the buyer has trouble meeting the purchase price or can't otherwise qualify for a conventional loan. This process is different from a traditional loan, because the seller doesn't give the buyer cash for the entire price as a typical lender would to make the purchase.