The Canon is a 'traditional' digital SLR in that it uses a mirror and viewfinder to show you the image through the lens optically and in real time. You also have the option of using the rear LCD for live view.
The Sony is a mirrorless interchangeable lens camera, which means that the camera lacks a viewfinder, and instead relies wholly on the rear LCD.
A few thoughts on both systems:
The Canon will be the larger camera (by a fair margin) as it has all the mechanics of the mirror, viewfinder and shutter mechanism to contain.
The Sony has none of this, so will be a much much smaller body.
The Canon has the viewfinder, which projects the image onto the focussing screen optically and in real time, without any lag in the digital processing needed to record and show the image on screen. This image is what is seen through the lens, and won't show the effects of different shutter speed or other camera settings though.
Alongside this the Canon offers you live view on the rear lCD allowing you to view the image on the back like a compact camera.
The Sony only has the rear LCD, which like the Canons live view will allow you to see the effect changing settings has, and show more information such as live histograms and various framing aides.
The Canon has the quicker autofocus when using the viewfinder.
The Canon also seems to be more of a 'system' at the moment - you have the larger selection of lenses given by the Canon EF mount, plus the use of various flashguns and other pieces.
The Sony is newer, so the lenses available are not quite as numerous, but are specifically designed to work with the system. It doesn't have the option to use external flash or other features though.
Basically to sum it up:
The Sony comes across as a high end compact camera - you are limited to using the screen, the lenses and accessories currently available and it isn't quite as powerful (slower af, inbuilt flash only).
The major bonus is in the small size and portability, and for everyday snaps it is a fantastically capable camera - think of a P&S camera on steroids.
The Canon is a 'proper' camera, so more features, more room to expand the system in the future and generally better handling and use, but at the cost of size.
If you just want a good quality, small, everyday camera, then the Sony is ideal
If you want to capture action, or want to get into photography more seriously the Canon will be the better camera to learn with and build on.
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