How the Digital Cameras work and what is the criteria to compare them. How to select the best digital camera?

(1)First compare the branding.. (normally ppl will buy cannon, becoz price is alright n affortable)
(Sony-->memory stick is "ex", if u want to get extra memory, u need to pay more compare to SD card or XD Card)
(panasonic--> not a camera maker company.
panasonic make gd electronics stuff like disc man)
(casio-->make gd calculater)
Get it??
(2)Second compare with ur budget..
(Get wat u need then wat u want)

(3)Third, Compare the function(Like wat u need n wat u dont need)(Like pixel, if u only want to develop 4r photo, u can choose pixel ard 5mp)(but if u wan to develop into Big photo size, u might need a higher pixel like 8 or more, so ur photo will not be blur after develop n stretch into a bigger size)

howstuffworks.com

Digicams have there megapixel range. It ranges from 2 to 8.1. The more Mega pixels the clearer the picture and also u can zoom without loosing the clarity of ur memories. Other important propertiees include battery backup and image compression.

depend to your needs.. size/zoom/speed/pixel? check www.bizrate.com for comparison or www.betterphoto.com for photo's Q&A/Forum

The best site to provide info about all manufacturers and even sample pictures is www.dpreview.com . Good luck

The best digital camera, like cameras in general, is dependent on what you want to do with it. any camera will take pictures and for many people that is sufficient. Hence the point and shoot designation. If you want to take professional quality photographs you need much better equipment. You will want a camera body that is capable of accepting different lenses. One that may or may not have auto focus, but with an auto-focus camera you will want a manual override. The same holds true for being able to control the aperture/shutter speed combinations available to you in any lighting situation. However, more than acceptable pictures can be taken with nearly any digital with auto focus and programmed exposure. My own personal preference is a thru the lens view of 5 mega pixels or greater; Nikon or Olympus. I own both, and use each differently.
Kinda like the old saying, "You don't hunt elephants with a BB gun."

Digital cameras captuer images in a similar way to film cameras. But record the image differently.
Instead of film they have either a CMOS (complimentry metal oxide semiconductor) sensor or a CCD (charged couple device).
To explain how these work would take too long here but if you go to http://lc.netcomm.com.au/CMOS_VS_CCD.htm this should help.
There are many, many criterium for selecting a digital camera and I'll attempt to list as many as I can.
Firstly price, what you can afford. next lens quality, then image size i.e. how many megapixels you need, build quality, battery life, weight of the camera, what you want to do with it.