Glossary
Review the definitions for terms used across Cloudflare's Magic Transit documentation.
| Term | Definition |
| letter of agency | Sometimes referred to as a Letter of Authorization. A document that authorizes Cloudflare to advertise your prefixes. This is required so transit providers can accept the routes Cloudflare advertises on your behalf. |
| policy-based routing | Policy-based routing (PBR) is a technique used to make routing decisions based on policies set by your administrador. |
| prefix | A number that identifies the network portion of an IP address. It tells devices if an IP address is on the same network or not. It is shown as a number after a slash (for example, Using an analogy, the prefix is like a street address. If an IP is in the same street, it belongs to the same network of devices. |