What is long term potentiation

Its a memory thing. The brain has short & long term memory & learning is chemically based between cells in various parts of the brain, We have the same amount of neurons in our brain & it doesn't increase no matter how much we learn. some short memories we can hold for 15-30 seconds & some long term memories we can hold forever depending on the chemicals & how they fire off with each other. How we access these memories depends on our they are triggered off in the brain, chemically speaking. I think this is a simplistic & basic way of explaining.