Perhaps the most popular myth that many many people have toward cameras is that the megapixel count is everything. Many people believe that it is the main way to judge a camera's worth, and the more megapixels, the better. If you have a 14 megapixel Sony point-and-shoot and I have a 8 megapixel dSLR, then definitely the Sony is better as it has more megapixels.
This is what so so many people think, especially the non-technical users. Not surprisingly then, this myth is also constantly exploited by camera manufacturers in their advertising gimmicks. So many people have purchased cameras just because the salesman told them the camera has a high megapixel count.
But the here's the truth, the one and only truth: megapixel count is only an indication of the image resolution and hence how much detail the camera can resolve, but it DOES NOT say ANYTHING about image quality at all!
It only tells you the resolution, that is how many pixels you have horizontally and vertically in the captured digital file. In other words, that 8 MP dSLR will most likely produce better image quality than the 14 MP Sony compact, but the resolution of the digital file from the dSLR will be smaller than that from the Sony of course. Contrary to popular misbelief, more megapixels in a consumer point-and-shoot seldom produce better images, because it actually causes image quality to drop, and in most cases, to have more noise at higher ISO and reduced contrast (though resolution increases).
So what does image quality depend on then? What it boils down to is really the lens optics and also the digital sensor used to capture light. This is what people should be looking for in a camera, and this also explains why compacts suffer from poor image quality as compared to dSLRs. As the name suggests, compact cams have a small sensor size in order to fit into the compact body. However, dSLRs, being bigger, can afford to have much larger sensors which will perform better in low-light and yield better images. Second factor affecting image quality is lens optics, that is how good the glass is. That's why SLR lenses are typically so costly. A better lens would produce better colours, suffer less from chromatic abberation, have less distortion and have a higher resolving power. This translates to better image quality.
Lastly, I must also clarify that megapixel is NOT a measure of image sharpness. Sharpness depends on your lens, your shooting technique (whether you can steady the camera or not) and the level of sharpening the camera's processor applies to the JPG files.
With all these shocking things in mind, realise that besides megapixels, there's much to consider in purchasing your new camera. Consider the lens, the zooming power, the low light performance, the sensor, the image processing chip, the colours... there is so much other than megapixels.
So in summary, do not be fooled into thinking that a 14 MP camera is always a good thing. What megapixels mean is just resolution. In real-world usage, this means how big you can print your digital file up to. So unless you are printing super big 20 inch prints, you don't really need that much resolution. Typical cameras today have an average megapixel count of 8-12, and that's sufficient for most users. More megapixels only means larger file size (loads slower on the computer) and unnecessary resolution.
Hope this clears things up! The next time people come up to you with your camera and the first thing they ask is 'so how many megapixels?', you know what to tell them!