Crossword diagrams, also known as grids, are a popular form of word puzzle. They consist of a pattern of squares, usually arranged in a rectangular grid, which contain clues for words that must be filled in. The patterns of the grids are designed to provide a challenge to the solver, and the clues are often cryptic or pun-based. The grids can be symmetrical or asymmetrical, and the words can be placed horizontally, vertically, or diagonally. Solving crossword diagrams requires knowledge of language, culture, and trivia, as well as problem-solving skills.