10DLC numbers have a local prefix. Toll-free numbers have a standard prefix like 888 or 833.
10DLC numbers are also a way for businesses to send over dedicated application-to-person routes for business messaging. There are restrictions and guidelines for what you can send over A2P 10DLC numbers.
Sending messages over 10DLC numbers can be less expensive than toll-free or short codes, for that matter.
While there is a verification process for both number types, the approval process for a 10DLC number can take longer to complete than toll-free number.