Gaps is one of my personal favorite solitaire card games. Your trying to line up the cards from 2 - King by suit. The cards have been dealt into four rows with the 2s on the far left. The aces have been removed to form Gaps. You can move a card into a gap if the value of the card is one more than the card to the left of the gap and has the same suit. You can also move a card into the gap if it's one less than the card to the right and has the same suit.
Cards that are in the proper order get highlighted in yellow. When you get stuck you can click the 'Shuffle' button and it will shuffle all the cards that are not highlighted. You can click the 'Shuffle' button up to 3 times in any game.