Christmas tree material:
Usually, artificial Christmas trees and their needles are made up of using two materials. One is PE while the other one is PVC. Each of them has its benefits. Thus, it depends on you which tree you are looking for and which one will suit you the most. Based on that, you can select the material of your tree.
The color of PVC trees does not fade away, and it will remain green forever. This material is also resistant to fire. That makes it safer as compared to a real tree. However, the manufacturer wires the PVC needles to the branches. That makes the tree seem more fake instead of natural. Some of them also get sculpted for a more authentic feel.
If you want a tree that looks real, a PE one would be a more suitable choice for you. Some of the trees also use both materials to provide variation to the needles.