Canon makes several series of non-SLR digital cameras; each line of cameras begins with a letter-number designation. The A series is the entry-level tier; they're the least expensive but they also lag in features. The Sx00 Elph series is the most compact. The SX series is mid-tier—larger and more powerful. The G series is the top: it has a lot of the EOS features but lacks interchangable lenses.
My mother's first digital camera (and the first in the family). Nice little guy; she wore it out.
For more information: Canon Camera Museum
Camera manual: Orphan Cameras.com