RC4 is a widely used stream cipher that encrypts data one bit or byte at a time, creating a continuous stream of encrypted data. AES and DES are block ciphers, and SHA-256 is a cryptographic hash function.
RC4 operates by generating a pseudorandom stream of bits, which is then XORed (exclusive OR) with the plaintext to produce ciphertext. This process allows RC4 to encrypt data one byte at a time, making it suitable for applications where a continuous stream of encrypted data is required, such as secure communication over the internet.