A database is software that manages data inclduing storing, indexing and performing queries. Some are internal to an application, but many run as a service used by multiple applications, either running on a central computer or using some form of cloud service. The most common forms are relational databases (effectively collections of large, interconnected tables) and noSQL databases, which use simple key-value bindings to JSON objects.
Used on Chap. 2: pages 23, 24, 25; Chap. 3: pages 37, 48, 51; Chap. 5: page 105; Chap. 10: page 200; Chap. 12: page 275; Chap. 13: pages 290, 297, 306, 307, 311; Chap. 14: page 338; Chap. 16: page 371; Chap. 17: pages 392, 397, 398; Chap. 21: page 516; Chap. 22: page 535