Wikipedia defines the term to be “a difference of opinions between one generation and another regarding beliefs, politics, or values.”

In layman’s terms, this leads to differences in opinions most often between parents and children and grandparents and children.
In this sense, the generation gap morphs into a generational clash.

This generation gap arises due to the evolution of time.
Older generation people have limited access to technology and gadgets thus their way of thinking differs from the younger generation people.
The modern ideas of the current generation are opposed to the traditional views of the previous one.

The belief systems of both are vastly different as well, leading to a gap.
Lack of healthy and proper communication between generations may also lead to a generation gap.
Generational gaps sometimes may lead to difficulties in relationships within a family.

Thus, each generation must learn to respect each other’s opinions and resolve conflicts.