"A chemical reaction in which a highly reactive species(or element) displaces or pushes out a less reactive element from its solution is called displacement reaction."
For instance, zinc removes iron ions from iron sulfate solution.
Copper nitrate solution releases copper by reacting with iron to form an iron sulfate solution.
A displacement reaction is also referred to as a substitution reaction.
The chemical equation of a displacement reaction:
For example, the displacement reactions include the reaction of iron and copper sulfate, which results in the production of iron sulfate.
As iron is much more reactive than copper in this situation, copper is replaced.