In Unity, you normally use scriptsA piece of code that allows you to create your own Components, trigger game events, modify Component properties over time and respond to user input in any way you like. More info
See in Glossary to create functionality, but you can also include code created outside Unity in the form of a plug-in. You can use two different kinds of plug-in in Unity:
Managed code is accessible to the standard .NET tools that Unity uses to compile scripts. The only difference between managed plug-in code and Unity script code is that the plug-ins are compiled outside of Unity and so Unity might not be able to access the source. When using native plug-ins, Unity’s tools can’t access third-party code libraries in the same way that they can access the managed libraries. For example, if you forget to add a managed plug-in file to the project, you will get standard compiler error messages. Whereas, if you forget to add a native plug-in file to the project, you will only see an error report when you try to run the project.
The following pages explain how to create and use plug-ins in your Unity Projects:
2018–03–19 Page amended
MonoDevelop replaced by Visual Studio from 2018.1