What are the differences of the series of Canon digital cameras?

For example SD series, A series, E series, etc. I just want to ask in general, not in specifications. Thanks.

Public Comments

1. size, features, and price
2. A great site for research and comparison on digital cameras is dpreview.com
3. The A series use "AA" batteries, so you can use store-bought disposable batteries or rechargeable "AA" batteries. They are somewhat larger. They offer manual exposure control. The SD series are smaller and will fit in a shirt pocket. They use rechargeable Li-Ion batteries. They only offer limited exposure control.