the photosynthesis is the process that makes trees and other plants meaningful for us. It's like a coop game, we (humans and animals) give the plants CO2 and the plants give us O2. But not only our normal CO2 usage (without cars and stuff) is enough for air filtration. The plants also need sunlight and water. the plant's leaves absorb water, CO2 and light and put it into their chloroplasts.
Chloroplasts are small organelles inside the plant. Then all 3 ingredients are transformed into glucose and O2 (oxygen). The plant keeps glucose and lets the O2 free because the plant doesn't need the O2 and we breath it in and CO2 out. So it's an endless circle but we stop that endless circle when we chop more and more trees. The photosynthesis is vital for all of us so remember to be green, stop chopping trees, don't eat stuff containing palm oil and be fair to nature.😊