Type libraries add many useful features to the COM libraries.
One of these is Visual Basic Intellisense. The type libraries provide Visual Basic with information so that it can help you with code completion. It prompts you with the format of the method and, where applicable, constants which might be relevant to method parameters or return values you can test for. For example if you create a terminal object for Visual Basic as shown in the example in Object creation and interfaces, when you want to select a method on the terminal object, press the '.' key and you are presented with a list of available methods. Select the method and press space or open bracket and you are shown the required parameters. You can also browse the type libraries for reference information on the ECI and EPI classes by using the Visual Basic Object Browser. Select either CclECILib for ECI classes reference or CclEPILib for EPI classes reference information. The type libraries are embedded within the in-process library files cclieci.dll and ccliepi.dll.