Caesar Cipher : a technique for encryption that shifts the alphabet by some number of characters
Cipher: the generic term for a technique (or algorithm) that performs encryption
Cracking encryption: When you attempt to decode a secret message without knowing all the specifics of the cipher, you are trying to "crack" the encryption.
Decryption: a process that reverses encryption, taking a secret message and reproducing the original plain text
Encryption: a process of encoding messages to keep them secret, so only "authorized" parties can read it.
Random Substitution Cipher: an encryption technique that maps each letter of the alphabet to a randomly chosen other letters of the alphabet.