What is the difference between a limiting reactant and an excess reactant?
The “limiting reagent” defines the maximum amount of product that can be produced from the reaction.
The “excess reagent” is the one that will have some left in the solution after reacting completely (as much as possible) with the limiting reagent.
These are pretty easy terms because they mean in chemistry just what they do in normal applications. The “limiting” item limits whatever can happen – in this case a reaction. Once it is all used up, no further reaction can take place.
In the same way, the other compound(s) are “excess” - there is more of them than can be used by the other compound.