A type library is a file that contains type information about Windows Component Object Model (COM) objects. Type libraries do not contain the objects that they expose. Rather, they contain type information about classes, which describe objects. Each class, in turn, lists the properties, methods, and events of an object. By referencing a type library, ATEasy can determine the characteristics of the COM objects that the library describes, such as their properties, methods, and events. With this information, ATEasy can invoke an object's methods, using that object in an application. For example, you could insert the Microsoft Excel type library into an application and then use an Excel spreadsheet in the application.
Some type libraries contain ActiveX controls. If you insert a type library containing an ActiveX control into your ATEasy application, any controls described in the type library become accessible on the ATEasy Controls Toolbar. From the toolbar, controls can be inserted on ATEasy forms. For more information about using third-party ActiveX controls, see Adding Third Party Controls.