Also on the other Voynich wiki [1]

In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is encipherment. To encipher or encode is to convert information from plain text into code or cipher. In non-technical usage, a "cipher" is the same thing as a "code"; however, the concepts are distinct in cryptography. In classical cryptography, ciphers were distinguished from codes. Codes operated by substituting according to a large codebook which linked a random string of characters or numbers to a word or phrase. For example, "UQJHSE" could be the code for "Proceed to the following coordinates". When using a cipher the original information is known as plaintext, and the encrypted form as ciphertext. The ciphertext message contains all the information of the plaintext message, but is not in a format readable by a human or computer without the proper mechanism to decrypt it.

More information on the Wikipedia page [2] (with associated category list ]https://en.wikipedia.org/wiki/Category:Ciphers]) and the article on classical ciphers is [3], with the category list for the latter being [4].

The Wikipedia timeline of cryptography is [5].

An essay on ciphers can be found here [6].

Wikimedia images connected with ciphers can be found at [7]

There are various arguments that the Voynich Manuscript is a complex cipher - but the translations provided are widely inconsistent and are not provided for more than a page or so (and the VM does appear to be a running text).

Cipher machines include the Enigma Machine and the Lorenz cipher.