An engine is a section of an application that determines how that application manages and manipulates a type of data. From a developmental standpoint, an engine can also be application or module with an open application programming interface (API) to which your application passes data in order to accesses the engine's processing capabilities.
An engine can be another application, such as the Microsoft Help for Windows CE system. Applications pass Help files to the Help system, and Help for Windows CE displays those files. An engine can also be part of the operating system (OS), such as the spelling checker. An application passes the spelling checker text strings, and the spelling checker checks the spelling of the words in those strings.
This section discusses the Help and spelling checker engines, how they work, and how you can use their capabilities in your applications.