And double displacement reactions are also known as metaphosis reactions. So let's look at a single or substitution chemical reaction. So A plus B or AB plus C. What happens is that the bond between A and B is broken. So B dissociates from A forming its own reactant, while A C combines with A displacing this B. So basically, C kicks out our B and forms a bond with A forming AC plus B. And this is a single displacement reaction or substitution reaction.