introduction-to-com-and-atl.md

title	Introduction to COM and ATL
ms.custom	index-page
ms.date	11/04/2016
helpviewer_keywords	COM, and ATL ATL, COM COM objects, ATL
ms.assetid	35d6ae9c-abbb-42f0-9344-33f3c19ac3ce

Introduction to COM and ATL

This section provides a brief introduction to COM and ATL.

In This Section

Introduction to COM
Provides an overview of the Component Object Model's (COM) fundamental concepts, including interfaces, IUnknown, reference counting, QueryInterface, marshaling, and aggregation.

Introduction to ATL
Discusses, briefly, what the Active Template Library (ATL) was designed for, template libraries, and ATL version numbers. Includes recommendations for choosing between ATL and MFC.

Related Sections

The Component Object Model
The Windows SDK material on COM.

ATL
Provides links to conceptual topics on how to program using the Active Template Library.

ATL Class Overview
Provides reference information and links to the ATL classes.