The terms Lien and Encumbrance are often used interchangeably but there are differences. All Liens are Encumbrances but not all Encumbrances are Liens.
A Lien on Property uses the Property to secure a loan from a lender to a borrower. A Perfected Lien is a lien that has been recorded with a legal authority. For Property Liens, the lender usually files a Deed of Trust with whichever agency is responsible for recording Property Deeds. By filing and recording Liens a lender gains protection from other parties making claims against a Property. A Perfected Lien gives a lender priority in the event that the borrower fails to make payments on the Property.
An Unperfected Lien is a Lien that a lender has not filed with the correct legal authority. As a result other creditors can make claims on the property.
A creditor with a Perfected Lien takes priority as far as being paid for the secured debt over creditors with Unperfected Liens.