The displacement reaction is one in which one element displaces another element from its compounds.
For example,
Fe (s) + CuSO4 (aq) → FeSO4 (aq) + Cu (s)
Iron has displaced copper from copper sulphate solution.
Other Examples
Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)
Pb (s) + CuCl2 (aq) → PbCl2 (aq) + Cu (s)
Since zinc and lead are more reactive metals than copper, therefore they displace copper from its compound.