Sorry terms one gets used to.
Image reference quickly made up not the greatest but should serve.
is an n-gon. A ploygon of over 4 vertices. It is not actually a quad despite looking ‘square’. Note red circles, extra verts so not a quad.
is a tri (angle) simple enough, but the same applies, if one edge was subdivided it would look triangular but be a Quad, due to vert count.
All quads with a central ‘Pole’.
A pole is a vert where 3 or more edges meet. This one has 6, that is not a big disaster but generally better to be no more than 5.
Quads, come in many shapes. and are the foundation of good topology, as they enable loops. A cut from one edge directly to the other opposite edge. If you have 5 verts or 3 making the face there is no ‘opposite’ edge, so loops stop.
a 5 pole standard and important for turning loops directions.
a 3 pole standard and important for turning loops directions.
technically a 4 pole, but loops can only go straight, (well without very distorted topology)
The green dashed lines show loop flow round poles. See how number 7 tends to straightness, and the important 3 and 5 poles (numbers 5&6) change the direction of a loop.
Quad topology is important for these loop flows. It is also important for subdivisions, particularly the subdivision surface modifier. Quads subdivide neatly into 4 more quads.
You can test what problems subdivision can have by first adding a plane, and right clicking it, and selecting subdivide.
All works nicely!
Now with another plane select one edge and subdivide it so the plane now has 5 verts not 4.
Select all the now 5 vert plane, and subdivide it too. Go to vert mode to see what it did, as it did not make extra faces, it could not.
Imagine that topological chaos on a multi thousand vert character.
Taken from the web, the Main loops for a human head. It may need slight differences following Orc shapes! Look for the poles and how they turn the loops.