Chess Strategy and Tactics
Tactics are short-term calculated sequences of moves resulting in checkmate, the win of material or some other gain. An understanding of tactics is crucial to playing good chess; most games, especially at the club level, are decided by tactical mistakes.
No chess player can calculate an entire chess game from beginning to end. Even the best computer programs running on the fastest hardware can only "see" a limited number of moves ahead. Beyond what we can calculate, we must rely on strategy to guide us in finding the best plans and moves in a given position.
Chess strategy includes a wide range of concepts, from how to value the pieces to how to evaluate a position. Mastering these principles will greatly improve your understanding of chess.
Over the course of chess history, the first few moves of the game have been studied extensively, and fierce debate has raged as to the correct way to start out. Now, opening theory is an extensive field of study for top players, with some lines being analyzed well past the 20th move. While this much knowledge isn't necessary for most players, knowing the basics of your favorite openings can be the difference between gaining a quick advantage and falling into a known trap.
Many players think of studying endgames as a chore, but a little endgame knowledge can go a long way. Having a better understanding of the endgame than your opponent can change a lost position into a winning one.