All the techniques we present here can be divided into two categories, static techniques and dynamic techniques.

• Static Techniques can be applied at any time throughout the game, as they depend entirely on the numbers that are present in the game board right from the start
• Dynamic Techniques can only be applied at certain times during the game, as they depend on your progress and which cells you have painted (set) or circled

Clearly, at the start of a game, we have not set or circled any cells, so we have to rely on static techniques to make the first move. From then on, your next move is up to you, and you will use a combination of static and dynamic techniques until you solve the board.