The latest edition of the definitive guide to the Ada language covers the full details of the core language Ada 2012 as updated by the 2016 ISO Corrigendum and introduces the key new features in Ada 2022. The book is in four parts. It begins by introducing the fundamental concepts for newcomers, before moving onto algorithmic aspects and then structural features such as OOP and multitasking. The fourth part gives details of the standard library and interaction with the external environment. Six complete executable programs illustrate the core features of the language in action. The book concludes with an appendix focussing on the new features in Ada 2022. These new features aid program proof and the efficient use of multicore architectures.