This chapter deals with one of the important types of graphs which is derived from nature. We are aware that many concepts of science, technology, social science, philosophy, etc. originate from the various activities of the nature. In nature, one of the important entities is the tree. A common man cannot see the same trees that a mathematician can see. This chapter demonstrates the concepts of trees, properties of trees, traversal trees, spanning trees and minimum spanning trees. Every concept of this chapter is defined by using the BEIMI philosophy. This chapter provides real-life examples for the better understanding of the concepts. It is focused on finding the shortest path among vertices by using various algorithms. The chapter concludes with case studies and exercises aimed at connecting theoretical relational structures to real-world applications across various disciplines.