The reaction given below is an example of:
Ba(OH)2(s)+2CuCNS(s)→Ba(CNS)2(aq)+2CuOH(s)
The above reaction is a double displacement reaction. In the double displacement reaction, the two compounds react with each other, and the positive ions (cation) and the negative ions (anion) of the two reactants gets interchanged, forming two new compounds.