Compare and contrast block cipher with stream cipher.

What will be an ideal response?

The two major types of encryption algorithms are block ciphers and stream ciphers. A block cipher encrypts groups of text at a time. For example, a block cipher encrypts the whole word cat instead of encrypting each letter.  A stream cipher encrypts cleartext one bit at a time to produce a stream of encrypted ciphertext, so the letters c, a, and t in cat are encrypted separately.