Every device--PCs, routers, IP cameras, and printers--on a network has an IP address, a unique number that is used to connect to that particular system. A dynamic IP address is one that is not guaranteed to remain the same.
Many Internet Service Providers assign you a dynamic address. If you are broadcasting video from WebCam Monitor, a viewer can connect to you by typing your IP address, for instance "mms:///123.123.123.123". If your provider changes the address, the connection will not work.
There are several services, such as no-ip.org, that offer a solution to this problem. You can register for a free account, and they will assign your PC a name. The name will always allow someone to connect to your PC, even if its IP address changes.
