How many types of elements together make up the xylem tissue? Name them.

The xylem is a specialised tissue that is present in vascular plants that carries water and nutrients from the roots to the stems and leaves. Additionally, it offers mechanical assistance and storage.

Four main types of components make up the Xylem:

Tracheids: These are dead, tube-shaped cells with a tapered end. They have a thick lignified wall but no protoplasm. Their main function is to transport minerals and water. And they are abundant in lower angiosperms and gymnosperms. 

Vessels: These are present in angiosperms. These are long tube-like cylindrical formations.
The central hollow is rather large, and the walls are lignified. They lack protoplasm and are also non-living.
mainly involved in mineral and water conduction, as well as giving the plant mechanical strength.

Xylem Fibre: These are dead cells that have been lignified, with a central lumen. Two of its functions include water transportation and mechanical support.

Xylem Parenchyma: These are the only living cells in the xylem and they store fat and starch. They facilitate the short-distance transport of water.