How to apply different textures to one model?

How can you make a texture map that looks like the one used in the Unity Robots Lab?
I only can make one texture that applies to the whole model.
I have a model of a house and I need the roof and the exterior walls and the windows to have different textures. How??
See the texture map of the robot arm in the unity robots test lab

Do you mean a texture atlas? Texture atlas - Wikipedia

You need to be able to adjust the UV coordinates of your mesh in order to tell it what parts of the texture you use. This is something you would do in a 3d modelling program such as 3ds max or blender although it can be done in code.