A Poké Ball is a spherical device used in the Pokémon franchise to catch and store Pokémon. It is a key item for trainers, allowing them to capture wild Pokémon and carry them for battles or training. The design typically features a red top half, a white bottom half, and a black band in the center. There are various types of Poké Balls, each with different catch rates and effects. For example, the Great Ball has a higher success rate than a standard Poké Ball, while the Ultra Ball is even more effective. Trainers choose the appropriate ball based on the situation and the Pokémon they wish to catch.