Blender Rigging process. Is skinning a must? I'm new to Blender, not so new to Unity.

I built a 3D human model using Make Human, imported it to Blender, and used the following tutorial.

Using Blender And Rigify

I set up a an Armature, rigged it and deleted WGT bones.

Now, the tutorial says that I need to skin the rig to the model, but, after I added the armature and parented the rig to the mesh as the tutorial says, I already had the model rigged, I was able to animate and to import it to Unity with everything configured correctly.

So, why is the section Skinning the Rig to the Model there and how was I able to do this without the skinning process the tutorial mention? I am sure happy to be able to skip this, but it makes me feel like there is something I do not understand.

Maybe in Blender 2.69 the skinning process is included in the parenting?
When you press Ctrl P and select With Automatic weights, blender sets up all the vertex groups for each bone. Blender uses the mesh closest to the bone for each vertex group.

In some cases With Automatic weights will work very well, if you have good bone placement. Other times you will have to tweak each bone's weight (the vertex group).

The unity tutorial talks about skinning specific bones to use with unity's Mecanim.