What are the main classifications or categories of elements in the periodic table?

Alkali metals, Alkaline Earth metals, Transition metals, Basic metals, semi metals or metalloids, Non-metals, Halogens, Noble gases, Lanthanides and Actinides.

They are all full and don't need any more electrons in there outer shell.

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.