A crossword puzzle is a word game that consists of a grid of squares, where players fill in words based on given clues. The words are arranged horizontally and vertically, intersecting at certain letters. Each square in the grid can be either blank or filled with a letter, and the goal is to complete the puzzle by solving all the clues. Crossword puzzles can vary in difficulty and size, ranging from simple puzzles in newspapers to complex ones in dedicated puzzle books. They often feature themes or specific categories, making them a popular pastime for people of all ages who enjoy wordplay and problem-solving.