Secured loans are guaranteed by something of value, such as your home or personal savings. The lender has a claim to this property as payment if the borrower defaults on the loan. Secured loans, such as home equity lines of credit, come with less financial risk for the lender, so they will typically offer lower rates.
Unsecured loans, such as most credit cards and personal loans, are not backed by any assets. This gives borrowers the freedom to avoid using collateral, but the rate is typically higher than for a loan with collateral.