These are both camcorders that are created by Canon. These are known to be smaller than the typical camcorder that you can get in the past. There are fewer moving parts that are available so the battery life will also be longer than usual. The HF11 is considered to be an upgrade of H10 but the upgrades are not very evident. Some differences are the memory card that may come with these camcorders.
The HF11 also comes with a higher bitrate which means that it will be able to record clearer videos in low light conditions. The cost of the HF11 is also known to be more expensive as compared to the HF10.