Spider Solitaire is played with 2 decks of cards. Depending on the difficulty level you are playing, cards are either:
In Spider Solitaire, the goal is to build stacks from King down to Ace of the same suit, in the tableau. When a complete sequence has been built, that stack of cards is automatically moved to the foundation.
When all cards have been moved to the foundation piles, you win the game.
Though you can move any suit of card onto the next higher card of any suit, only sequential groups of cards of the same suit are allowed to be moved as a group. And as already mentioned, only a sequence of Kings descending to Aces of the same suit will be moved to the foundation piles.
Cards are also found in the stock. When you deal from the stock, 10 cards will be dealt at once, one to each of the tableau piles. In traditional Spider Solitaire rules, you aren’t allowed to deal from the stock unless every tableau pile has at least one card.