"This code replaces letters with numbers."
The A1Z26 cipher replaces each letter with its place in the alphabet, so A is replaced with 1 (since it's the first letter of the alphabet), B is replaced with 2, and so on.
"This is a simple substitution cipher."
This code uses the ROT13 substitution cipher, in which each letter of the alphabet is rotated 13 steps.
"This one is the pigpen cipher."
Also called the masonic cipher, Freemason's cipher, Napoleon cipher, and tic-tac-toe cipher, the pigpen cipher replaces letters of the alphabet with shapes that are part of a grid.
"I don't think you're ready for this jelly."
This code uses the Caesar cipher, the code that Julius Caesar used to encode his messages. He simply replaced each letter with the one three spots ahead.
"I like big butts and I cannot lie."
For this substitution cipher, the alphabet is rearranged randomly instead of in a set pattern.
"Apple bottom jeans, boots with the fur, the whole club was looking at her."
This was a combination cipher, first using the Caesar cipher (where each letter is replaced with the letter three steps away) and then putting the resulting code through the A1Z26 cIpher (where every letter is replaced by the number of its order of the alphabet).
"She had dumps like a truck, truck, truck."
This code uses the columnar transposition cipher, where using the keyword "CODES" (see it in all caps above the message?), each letter of the message is written in rows underneath. The letters are then read out from top to bottom in a chosen order. In this case, the order is the alphabetical order of the keyword, so the letters under the C are read first, then the letters under the D, then E, then O, and then S.