A neutralization reaction is very much like a double replacement reaction, however, in a neutralization reaction the reactants are always an acid and a base and the products are always a salt and water.
The basic reaction for a double replacement react takes the following format:
#AB + CD -> CB + AD#
we will look at an example as Sulfuric Acid and Potassium Hydroxide neutralize each other in the following reaction:
#H_2SO_4 + 2KOH -> K_2SO_4 + 2H_2O#
In a neutralization reaction between an acid and a base the typical outcome is a salt formed by the positive ion from the base and the negative ion from the acid. In this case the positive potassium ion (#K^+#) and the polyatomic sulfate (#SO_4#) to for m the salt #K_2SO_4#.
The positive hydrogen (#H^+#) from the acid and the negative hydroxide ion (#OH^-#) from the base form the water #HOH# or #H_2O#.
This is explained in the answer to the question "Why does a neutralization reaction occur?"
The formation of the strong covalent H-OH bond of the water molecules, from opposite charge #H^+# and #OH^-# ions causes the exothermicity of the reaction and the fact that the amount of evolved energy per mole of water formed is more or less the same independently by the nature of the acid and bases that are neutralized, if these are strong.