Allows you admission for 4 days into Magic Kingdom, Epcot, Disney-MGM Studios, and Animal Kingdom plus an extra 4 admissions into Blizzard Beach, Typhoon Lagoon, Wide World of Sports, Pleasure Island, OR DisneyQuest. You can even hop between parks on the same day. Your pass expires 14 days after your first day of use. 

You can certainly add extra options onto your pass including the No Expiration Option. If you would like to add the No Expiration Option to your ticket, your unused days never expire. Your unused days are good for a future visit to Disney World.