RC5 is a symmetric encryption algorithm. It is a block cipher of variable block length, encrypts through integer addition, the application of a bitwise Exclusive OR (XOR), and variable rotations.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 4: Cryptography (page 153).