The periodontal pocket is a key feature of periodontal disease that results from the deepening of the gingival sulcus. Pockets can be classified as gingival, suprabony, or intrabony depending on their location relative to the alveolar bone. The document describes the signs, symptoms, clinical features, and histopathological changes that occur as the gingival sulcus transforms into a periodontal pocket through collagen destruction and epithelial downgrowth along the root surface. Bacteria can invade the soft tissue wall and contribute to further inflammatory changes in the pocket.