A computer has a static address on the Internet if the address is manually added to the configuration and never changes. If you have a static IP address, select this option. You will be prompted for an IP address after you click the Generate Firewall! button.
If your computer receives its Internet address dynamically from a provider, it has a dynamic address instead. Most computers that connect to the Internet do so dynamically. DSL and cable broadband connections generally use DHCP. Dial-up connections typically use PPP or SLIP. All of these options are types of dynamic IP address assignment.