In simplest terms, leasing your minerals gives permission to the leasing company to look for, and potentially extract and sell the oil and gas. The lease will have terms and a royalty rate. The lease rate, or royalty rate, is your share of the oil and gas, if and when they are extracted, processed, and sold. Leases can expire, and alternatively, leases from years ago may still be valid. Leases are legal documents, so each one requires a signature.