What is transposition cipher?

A transposition cipher is a method of encryption that rearranges the characters of the plaintext to create ciphertext, rather than substituting them with different characters. This technique involves shifting the positions of the letters based on a defined system or key, maintaining the original characters but altering their order. Common examples include the rail fence cipher and columnar transposition. The security of a transposition cipher relies on the complexity of the rearrangement and the secrecy of the key used for the transposition.