- ActiveX - A program module that can be inserted into an ActiveX container such as a VB program, or Internet Explorer. ActiveX components have their own functions and behaviours inherent to them, and these can be utilized by the programmer whether he is making an executable file or a web page. ActiveX is the latest incarnation of the custom control line, replacing the outdated OCX's.

- API - Application Programming Interface. A collection of pre-existing functions inherent in windows that you can call upon to do jobs for you within the windows environment. These functions are stored within the multitude of DLL's that windows comes with.

- BitBlt - Bit Block Transfer. An API function that allows you to transfer a block of bits (A bitmap, for example) from one location to another. This can be used to move sprites around a screen, a prerequisite for making many types of games.

- DirectX - A set of API procedures that allow a programmer more direct access to the machine's hardware while still shielding him from a substantial amount of tedious machine specific coding. This is MicroSoft's answer to the complaints of programmers that windows was too slow to be a gaming platform. By allowing us access to the video, audio, and input devices directly MicroSoft has succeeded in convincing developers that windows is a viable platform for their games.

- DLL - Dynamic Link Library. DLL's contain procedures that can be dynamically or statically accessed by programs running in windows. Generally more than one program can access a single DLL at a time. Many DLL's come packaged with windows, others are created for the specific needs of a program. DLL's are useful since they reduce the need for redundant code within windows programs since the most frequently used procedures are centralized within the DLL's that make up the windows API.

- GDI - Graphical Device Interface. The method of operation windows operates under in order to maintain commonality of look and feel for all programs. The GDI defines how windows are displayed, bitmaps are moved around, etc. There is a file called GDI32.DLL that houses all of the API calls required to handle these operations (such as BitBlt).

- MCI - Media Control Interface. An API created for controlling multimedia devices such as CD ROM drives.

- OCX - OLE Custom Control. A program module available to other programs within the Windows environment. Where a DLL provides pre-made functions to windows programs, an OCX control provides pre-made controls complete with their own inherent functions and behaviours. OCX files are now out of date, and have been replaced by ActiveX controls, but backward compatibility has been maintained.

- OLE - Object Linking and Embedding. Pronounced oh-lay, you know, like spanish people say when the bull runs past the matador. OLE allows you to create an object within one program and link or embed it into another, thus allowing easily standardized formats. An example of this is how you can insert an Excel Worksheet Element into a Word document, and have it retain its functionality.