Figure 3.15 - Connecting vertices

You can also connect three and four vertices resulting in a face.

Selecting three vertices also creates a new face. However, it is a

common practice to avoid such types of faces. A triangular face usually

breaks edge loops and won't create smooth deformations in animations.

If you have two edges selected, you can also press the F key to connect

them with a face (Figure 3.16).