Trees are a diverse group of plant species that have separately evolved a trunk and branches in order to tower over other plants and compete with them for sunlight. Trees are not a monophyletic taxonomic group. Many of the remaining species of trees are gymnosperms or softwoods, while angiosperms make up the majority of all tree species. The average lifespan of a tree is hundreds to thousands of years. 370 million years have passed since trees first appeared. Around three trillion mature trees are thought to exist worldwide. A tree often has numerous secondary branches that the trunk supports above the ground. Typically, this trunk has circulatory tissues to transport materials from one section of the tree to another as well as woody tissue for strength. Trees are useful in our everyday they also provide various products like food, furniture, wood,shelter etc.Trees provide shade and shelter, timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In much the world, forests are shrinking as trees are cleared to increase the amount of land available for agriculture.If there were no trees, there would be no no human life. In one season a mature leafy tree produces as much oxygen as 10 humans breathe in a year. Many people are unaware that the forest also serves as a massive air filter, purifying the air we breathe. By capturing airborne particles, dissipating heat, and absorbing pollutants including carbon monoxide, sulphur dioxide, and nitrogen dioxide,trees contribute to air purification. By reducing air temperature,respiration,and particular retention, trees clean the air by removing pollutants.Forests already help to decrease flash floods, and more trees might further reduce it. When fully grown, a single Colorado blue spruce that is either planned or growing naturally may capture more than 1,000 gallons of water yearly. This decrease in water flow allows for the replenishment of underground  water holding aquifers.Drought is fought off by recharged aquifers.A tree uses the carbon dioxide iit receives anand stores in its woods roots anand leave leaves tto make  its nourishment.A majority of experts worldwide agree that carbon dioxide iis a “green house gas”and iis a significant contributor to both global warming and climate change.The amount of carbon that a forest can store,or “sink”, is equal to the amount that it can create. By “storing” carbon as wood through the locking-up process, it is prevented from being released into the environment as a greenhouse gas. Hence,trees plays a very major role in our life.