Full Mode & Zap Mode - Names possibly used for the display of an Electronic Program Guide (EPG). In this scenario, the "Zap mode" is where the EPG is only a partial overlay on the normal television program. Thus most of the what you see on the TV screen would be the regular program, with only a small part being the EPG. With "Full Mode", the EPG takes over the screen and you see a smaller amount of the program. See the Interactive Television Institute.