Tax liens and tax deeds are methods local governments use to recover unpaid property taxes. In a tax lien, the government places a claim on the property for the owed taxes, and investors can purchase the lien at auction, earning interest until the owner pays the debt or the investor forecloses. A tax deed, on the other hand, involves the sale of the actual property to investors when taxes go unpaid, transferring ownership directly. Both methods offer opportunities for investors to potentially acquire property at a discount, though they come with legal and financial risks that require careful due diligence.