Understanding good topology using grids
Good topology is a mesh that deforms the way you want and makes the shape you want with the fewest number of triangles. The easiest way to get clean topology is by using a quad-based workflow. A quad is a face that contains four edges and four vertices. Although it is considered a single face, it is technically two triangles combined. This can be seen in Figure 2.1. Because you can manipulate the vertices individually, it must contain two triangles.

Figure 2.1 – Quad made up of two triangles
If you were to take multiple quads and string them together to form a plane, you would get a grid as shown in Figure 2.2.
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Figure 2.2 – A grid (the perfect topology for a plane)
If what you were planning to make was a plane, this would be an example of perfect topology. Unfortunately, objects and characters are often a bit more complex. Thankfully, there are a few useful tools we...