The two definitions of packet sniffers are great, but the best of the newsletter is the link to "The Ten Commandments of Wireless Connectivity" also on their site. This is a great read, and very valuable information.
I offer just the first one here, to whet your whistle. The rest you will have to read on B&B's website.
1. Thou shall know thy dBm and recall thy high school logarithms.
Radio Frequency (RF) power is measured in milli Watts (mW) or, more usefully, in a logarithmic scale of decibels (dB), or decibels referenced to 1 mW of power (dBm). Since RF power attenuates as a logarithmic function, the dBm scale is most useful. Here are some examples of how these scales relate:
