Cryptographic algorithms
It is a type of substitution cipher in which each letter of the text is replaced by another, which appears in the alphabet below a fixed number of times. For example, with a three-position swap, A would be replaced by D, B would become E, and so on. The method is named after Julius Caesar, who used it to communicate with his generals.
The Vigenère cipher does not consist of using several Caesar ciphers in sequence, with different offset values dictated by a "keyword". To encrypt, an alphabet table is used consisting of the alphabet written 26 times on different lines, each one shifted cyclically from the previous one by one position.