DES has four modes of operations:

CBC - Cipher Block Chaining. In CBC mode, each plaintext block is XORed with the previous cipher text block and then encrypted.

ECB - Electronic Code Book. In ECB mode, each plaintext block is encrypted independently with the block cipher.

CFB - Cipher Feedback. In CFB mode, the previous cipher text block is encrypted and the output produced is combined with the plaintext block using XOR to produce the current cipher text block.

OFB - Output Feedback. OFB mode is similar to CFB mode except that the quantity XORed with each plaintext block is generated independently of both the plaintext and cipher text.

References: http://www.itl.nist.gov/fipspubs/fip81.htm