What is moss?

Moss is a very simple type of plant without conventional roots, stems, and leaves. It refers to any species of the class Bryopsida and is part of the division Bryophyta. Bryophyta means the first green land plants to develop during the evolutionary process. Moss is thought to have evolved from very primitive vascular plants. Moss has not given rise to any other kind of plant.

Because moss lacks traditional vascular structures of true leaves, stems, and roots, its growth is limited to moist locations. Moss is usually very hardy and grows almost everywhere, except under the sea. Moss usually grows vertically. Except for the commercially viable Sphagnum peat moss, moss is generally of little use to humans. It is also of little use to animals, although it is sometimes eaten in times of famine.

Moss grows rapidly and can be invasive. Why remove moss - HERE?
Moss is very easy and safe to remove. How to kill moss - HERE
Where can I apply the Moss Killers? Where to kill moss? - HERE