COM automation - technical definition

A particular usage of Microsoft's COM-based component software architecture that lets applications expose their internal functions as COM objects. Called "automation" or "OLE automation," it enables tasks that are normally selected from menus to be automatically executed. For example, a small script could be written to extract data from a database, put it into a spreadsheet, summarize and chart it, all without manual intervention.

Virtually any internal routine can be written as a COM object and its interfaces exposed to other programs. Microsoft applications such as Word and Excel are written as COM objects, and not only do they allow their functions to be automated, but they offer programmers a toolbox of functions that can save them the time and effort of writing similar routines themselves.