3D Model Planes, Edges and Vertices

In Blender, models are composed of these three items.
I thought I would give a quick overview geared more towards beginners starting out in 3D modeling on how some of this works and how it can benefit you knowing how to work with each type.
First off, faces. Faces are created when you fill in the gaps between vertices and create a plane out of them.
Say you have four vertices which make up a square.
Until you assign a face to those vertices, they are just four vertices.
Once you assign a face (by selecting all of the vertices and hitting the f button on your keyboard) now the mesh has a face.
It will also now have edges.
Your mesh will now consist of four vertices (dots or points) , four edges and one face.
You can think of it as each vertice being a corner, each edge being one of the edges of your square and the face being a face joing all of these together.
As you build your model, it simply becomes a combination of these all hooked together, creating a 3D model.
What I found interesting is that you can select two vertices and hit the F key and it will create an edge.
You can select three to four vertices at the same time and hit F and it will create a face, joining them all together.
If you think about it, you cannot have a face with less than three vertices, that is the minimal amount of vertices to create a face.
Extruding Also interesting is extruding each one of these. If you hit E for extrude while selecting a vertex, it will extrude out, creating an edge since you now have two vertices.
If you extrude an edge, you will be extruding 2 vertices at once, creating 4 vertices... thus creating a face. :)
If you extrude a face with four vertices, you have created a second Face, or 8 vertices, 8 edges.
If you are a beginner to 3D modeling, it can be fun to start with a vertex, and extrude to see what you can create and then add a face to them and see how it works.
This video will give you some examples on how extruding vertices or groups of vertices allow you to create both 2D and 3D objects.