interface keyword

It might help if you specified a programming language.

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A interface is like a set of rules for an object. All objects that can go into my 3D Engine Object Manager must implement my BasicObject interface.

In the interface I define only a simple thing, that all objects must have a render function. Without that, they are not allowed in my manager class. So all objects is based on this interface.

This is C# code:

public interface IBasicObject
{
void Render();
}

If the objects don''t have a render function and implements the interface, the compilation will fail.