The major difference between DSLR cameras and the Point-and-Shoot cameras is the size of the Sensor.
The Point-and-Shoot cameras have a much smaller sensor assembly which produces more noise.
If the camera has more than 12 megapixels, the camera maker must use noise reduction firmware to remove some of the noise. This also removes some of the small detail. If you print large pictures, the noise and lack of detail is obvious. The ISO setting at 400 will show some noise and anything higher, the noise is very noticeable.
This means that shooting in low light gives poor results.
There are a few Point-and-Shoot cameras that are above average in low light, but none of them have much zoom (about 3X).
The Panasonic ZS15 is worth a look-see.
It has better than average low light performance and has a good zoom.
I used to own a film SLR but got so tired of lugging around a camera bag full of stuff that I quit photography and disposed of all the equipment. Now, years later, I've discovered digital cameras and some even have zooms of more than 15X. That sounds like the perfect replacement for my old stuff. I know that there are DSLRs too, but that would get me back to carrying a lot of stuff around. Besides, I've read that most people with those cameras seldom change the lenses anyway.
Yet despite all the disadvantages of extra lenses, etc., serious photographers seem to prefer the DSLRs. Why would one put up with all the disadvantages of a DSLR when, for less money, one can buy a compact with high megapixels and high zoom? Is there such a big difference in quality?