Cipher techniques are methods used to encrypt and decrypt information, ensuring that only authorized individuals can read the data. These techniques transform plain text into coded messages, making it difficult for unauthorized users to understand the content. Common types of ciphers include Caesar cipher, substitution cipher, and transposition cipher. In a Caesar cipher, each letter in the text is shifted a certain number of places down the alphabet. A substitution cipher replaces each letter with another letter or symbol, while a transposition cipher rearranges the letters in a specific pattern. These techniques form the basis of modern cryptography, which is essential for secure communication.