What is the purpose of a whole home surge suppressor?
A whole-house surge protector is used for the same reasons that you use the power-strip surge protectors with your computers and TVs - to protect that equipment from power surges. The benefit of a whole-house unit, though, is that it protects everything connected to your electrical panel - your furnace, AC, water heater (if electric), washing machine, as well as your computers and TVs. Newer appliances have a lot of internal electronics, and the cost of replacing a fried circuit board can exceed the cost of a new appliance, making the installation of a whole-house surge protector a very attractive value.

Be sure to read the fine print of any warranty the surge protector comes with, as it may require professional installation. Typically, these units come as a double-pole breaker and are usually installed as one of the first breakers in the panel. Some of them have also a piece that sits outside the panel, and are installed through a knockout in the panel.

A lot of people will tell you to continue using strip surge protectors for your consumer electronics, and there really is no harm. Most of us need the extra outlets provided by the power strip anyway.