The digital SLRs are by far the most advanced cameras available in the market. A great asset of these cameras is that they enable the photographer see what the sensor sees, through the viewfinder. This ensures that the focus, composition and depth of field are perfect. Another advantage is that the lens can be changed according to the needs of the photographer, giving the photographer great freedom in carrying out assignments.
Another advantage of digital SLRs is the sensor size. Most digital SLRs have sensors that are six times bigger than the sensors used in point and shoot cameras. This means that the size and resolution of the picture shot with an SLR is far superior. Also, the noise level is much less.
The large sensor gives the photographer one more advantage. It allows the photographer to use a shallow depth of field to produce a blurred background. This is not possible with a point and shoot camera even if it has a high pixel count.
Even the viewfinder of a digital SLR is much bigger than that of a point and shoot camera. This gives the photographers a clearer and brighter view of the object a view that beats the one provided by an electronic viewfinder.
The lenses used in SLRs are more advanced than those used in point and shoot cameras. They can be used to focus better on objects. A particular advantage is using a macro lens with an SLR. This gives the photographer a much sharper image than in normal cases.
Another advantage is the dynamic range -- that is the brightness levels that a camera can capture. The digital SLRs have a high dynamic range, and can shoot pictures from the lightest to the darkest without losing details.
Also, there is virtually no shutter lag in SLRs. This means that there is negligible time lapse something like the millionths of a second -- between the pressing of the shutter and the camera registering the image. You can therefore get an image of what you saw when squeezing the shutter button.
This is not all. The digital SLRs can capture images in the RAW format, which is not possible in the point and shoot cameras where the camera's software modifies the image before saving. The image thus captured is quite suitable for further improvement because no loss of data has taken place at the image capturing or storage stage.
The flip side is the cost. The digital SLRs are far more expensive than simple point and shoot cameras. They can burn big holes in the pocket once the cost of the lenses and other accessories are added to the cost of the camera.
One should also not forget the size of digital SLR cameras. They are much bigger, and not as sleek as point and shoot cameras. But this should not be a dampener for any professional photographer who should be more concerned with the quality of the image than the shape of the cameras.