Typical wall voltage in the United States and Canada is between 110 and 120 Volts, alternating current, 60 Hz, as regulated by NERC. However, appliances (such as clothes dryers and ovens) that draw a lot of power often use 220 Volts. This is provided by using both legs of the incoming power to the house instead of just one.

When an electrician says "one ten", this is what he is referring to.

A 110 Volt electric shock is usually a painful experience, but this depends on a number of factors including: your body's natural resistance, the shoes you are wearing, how wet your skin is, whether or not you are touching something conductive, and many other things. If conditions are wrong, the electric shock could make your muscles contract, preventing you from letting go of the thing that is shocking you. If you are wearing a metal watch or ring, it could heat up and burn you very badly. If conditions are very wrong, 110 could even kill you.