NOTE: See How do I install Network Monitor?
Microsoft Knowledge Base Article 233032 contains the following summary:
Network Monitor 2.0 includes six experts. Experts are tools to help you analyze data by using built-in parsers. These tools automate
time-consuming tasks (such as looking for TCP retransmissions).
Note that Network Monitor provides for the installation of additional experts. You may have experts other than those listed here installed on your computer. For information about writing custom experts, see the Network Monitor 2.0 Toolkit.