Any chemists in the room?

I have been looking at definitions for certain processes and states that affect ceramic ware, and I came up with the following definitions... I find them a bit confusing. Is there anyone who can save me a few hours of deciphering what these mean (ignoring supercooling, which doesn't affect ceramics)?

Vitreous refers to a material in an amorphous, glassy state (in contrast to a crystalline state). In such a state, the constituent atoms do not exhibit the long-range order that is characteristic of crystals. However, they still exhibit short-range order -- the separation of atoms and/or the lengths of covalent bonds are very close to their typical equilibrium distances. The creation of a vitreous material by supercooling or by addition of additives prior to cooling is called vitrification.

Vitrification is a process of converting a material into a glass-like amorphous solid that is free from any crystalline structure, either by the quick removal or addition of heat, or by mixing with an additive. Solidification of a vitreous solid occurs at the glass transition temperature (which is lower than melting temperature, Tm, due to supercooling).