AES uses a mathematical equation a “key” to encrypt data into something unreadable. Putting very simply, lets say the data we are hiding is the number 2, and our key is “+2” the encrypted result is 4 (2+2=4). If you receive the encrypted data (4) do not know the equation (+2) you cannot get the original data because the number 4 can be the result of many equations (3+1, 5-1, 8/2)