Inflatable canoes are great because they enable you to carry lots of stuff and usually multiple people as well.  The difference between a hard shell canoe and kayak is very distinct; however the line is not so definite between inflatables.  The main difference is carrying capacity and how high you sit above the water.  Canoes will always have a higher seating position and greater storage capacity.  This is great for longer trips such as camping.  Canoes are always open top and are often bigger and deeper than Kayaks. 
 
It is important to note that inflatable canoes do not work very well in still water such as a lake, or flat stream.  They work best on moderately fast moving water such as small rapids or a swift river.  Some canoes are designed for sea use.  These generally are more resilient to large waves and salt water. 
 
Another crucial difference between canoes and kayaks is the [paddle].  Canoes are propelled with a single sided paddle, while kayakers use two sided paddles.  A single paddle enables stronger strokes, however it is more difficult to steer and often times beginners can find a single paddle confusing to operate.
 
In general, inflatable kayaks are more versatile boats, but inflatable canoes can be fantastic if you need to carry a lot of luggage or people down moving water or rapids.  Just like an inflatable kayak, when choosing an inflatable canoe other things to consider are the color, portability and ease of inflation. Take a look at the ebay listings below for more information of Inflatable canoes for sale.  Have fun purchasing!