Biological Classification

Step 1: Definition of Variation.
Variation refers to the differences in characteristics or traits among individuals of the same species or closely related groups. Step 2: Closely Related Groups.
In closely related groups of organisms, the variations could be in the form of physical characteristics, behavior, or other attributes. These differences are crucial for evolution and natural selection. Step 3: Conclusion.
Therefore, the differences in characters within very closely related groups of organisms are called variations.