Christmas trees can come in many different shapes and sizes. Traditionally, evergreen trees such as fir, pine, spruce, or cedar are used for their height, fullness, and long-lasting needles. These trees are typically cut down for the holiday season and brought indoors for decorating and display. However, other types of trees can also be used as Christmas trees, such as birch, holly, or yew, which have different shapes and textures. The choice of tree often comes down to personal preference and availability.