Christmas trees are an integral part of Christmas decorations. Although many people like to buy a Christmas tree for holiday decorations, few people buy its various types. So what is a Christmas tree? Many people think that the Christmas tree is a fir tree, and many people think that it is a pine tree, and many people think that it is a cypress tree. In fact, there is nothing wrong with it. There is actually no unified tree species for Christmas trees. As long as it is an evergreen tree in four seasons, it remains green in severe winter and looks full of vitality. The tree is tower-shaped and easy to hang decorations. It can be used as a Christmas tree. Generally, conifers and cypresses are more commonly used. Among the coniferous plants, including pinaceae plants, fir plants, and cypress plants, fir trees and pine trees are most commonly used as Christmas trees because of their suitable shapes and rich varieties. Cypress trees are not suitable for their shapes, so they are used less. Fir and spruce are the most traditional Christmas trees, and they are also the most commonly used Christmas trees in the world. They are beautiful in appearance, green in color, fragrant in smell, and their leaves are not easy to fall off. They are the most popular types of Christmas trees. Pine trees such as stone pine and scotch pine are often decorated as Christmas trees. Although cypresses are also used as Christmas trees, they are relatively rare, and even fewer other tree species. Therefore, Christmas trees cannot be simply defined as a certain type of tree species. Fir, pine, cypress or other tree species can be decorated as Christmas trees, but fir trees are the most commonly used, followed by pine trees, and other types are used less..