1. Port 1443 is the default port used by SQL Server but you can change it to some another port number at the time of installation 2. Port is required to make SQL Server available over the network. Nothing to do with working on databases if they are local.
Harsh Athalye India. "The IMPOSSIBLE is often UNTRIED"
Well port 1433 is the default port not 1443. For externally accessed databases, you should change the port to a 5 digit port and never post it on the Internet.