---
title: "Can you explain IUnknown interface used in COM ?"  
description: "Can you explain IUnknown interface used in COM ?"  
author: "Amit Singh"  
published: 2011-03-28  
updated: 2020-09-20  
canonical: https://www.mindstick.com/interview/681/can-you-explain-iunknown-interface-used-in-com  
category: "visual c++"  
tags: ["visual c++"]  
reading_time: 1 minute  

---

# Can you explain IUnknown interface used in COM ?

COM is an acronym for Component Object Model. COM is a way of building objects that is independent of any programming language. \
Every COM object implements an interface named IUnknown. It contains three methods:\
- QueryInterface: Returns a pointer to another interface\
- AddRef: Increments the objects reference count\
- Release: Decrements the objects reference count.

## Answers

### Answer by Amit Singh

COM is an acronym for Component Object Model. COM is a way of building objects that is independent of any programming language. \
Every COM object implements an interface named IUnknown. It contains three methods:\
- QueryInterface: Returns a pointer to another interface\
- AddRef: Increments the objects reference count\
- Release: Decrements the objects reference count.


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Original Source: https://www.mindstick.com/interview/681/can-you-explain-iunknown-interface-used-in-com

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