It is extensible(change the behavior of the container, or add new capabilities) and lightweight D.I (dependency injection) container for building loosely coupled applications.
You can use it in any type of .NET Framework-based application.
It provides all of the features commonly found in D.I mechanisms.
Also provides following advantages
1. Simplified object creation
2. Instance and type interception
3. Service location capability
4. Increased flexibility by deferring component configuration to the container
Source: unity.codeplex.com | |