Having read a few articles about computer performance, I often come across the "big four", the four components of your computer that might be impairing performance: 1) CPU, 2) memory, 3) hard drive, and the 4) NIC.
Items 1, 2, and 3 are pretty straight-forward. Item 4, however, is a complete mystery to me. Can someone give me an example how the NIC (or, potentially, a slow network beyond the NIC) might impair the computer's performance, and how I might examine network behavior to determine if that's my problem? How might I use Task Manager, Process Explorer, or some other tool?