Oxygen is a colorless, odorless gas that is essential for life on Earth. It makes up about 21% of the air we breathe and is crucial for the process of respiration, where living organisms convert food into energy. Plants, through photosynthesis, produce oxygen as a byproduct, helping to replenish the air we need. In addition to supporting life, oxygen is also important in various industries. It is used in medical settings to help patients breathe, in welding to cut and join metals, and even in the production of rocket fuel. Without oxygen, many processes that sustain life and technology would not be possible.