How does oxygen get into the atmosphere?

Oxygen in the atmosphere comes from plants and some bacteria. The fact is that the solid part of plants (stems, all woody parts) consists of carbon, which can be found in the atmosphere in the form of carbon dioxide. When this gas is absorbed by the leaves, the second component, oxygen, is released and released into the atmosphere. Considering that oxygen produced by plants is vital for the entire planet, it is very important to protect forests from deforestation and plant new ones.