This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Localhost is the name given to the local machine. It's mapped to 127.0.0.1 in your machine's host file.
By default, Tomcat ships configured to run on port 8080. This is most likely because it's first an app server and will often share a machine with a webserver (such as Apache httpd). You can configure Tomcat to run on port 80 by changing the port number in server.xml.
Note: On a Unix machine, only programs started by the root user can bind to ports below 1024. There are work arounds for this. Search this forum to find them. They've been discussed often here.