There are a number of things to be taken into account when choosing thebest compact digital camera. These cameras all vary in size and have different functions and onboard memory storage for the images so a little research is called for before you spend on a camera that will do what you want it to do. Consider such things as the operating environment, will the camera often be used outdoors in inclement weather like rain? If the answer to this question is yes, then you will want to consider a compact digital camera which can be used underwater without damaging any of the electronics or optics.
If you want a compact camera, look at those that will comfortably slip into your pocket, anything larger will have to be carried in a bag or slung around your neck. The size should be optimum for the user, small enough to easily carry but large enough to comfortably fill the hand. It should be easy to get to all the buttons, the buttons should be easy to press and the working menus should be easily navigated. Look for a model which has a large LCD display instead of a typical viewfinder, this makes setting up the picture much easier, you can take a quick look at the display to determine if the image is positioned as you want it and that it is not overexposed or underexposed. Most compact digital cameras are autofocus and auto exposure but the better units allow you to change both settings.
A compact digital camera will have some sort of onboard memory storage; the type of memory will vary between manufacturers and models. The common storage methods are compact flash cards (CF) and secure digital cards (SD). The smaller and most popular of the two is the SD card, this makes them light and easy to store but they are more fragile than the CF card. CF cards are usually employed on larger cameras such as a DSLR, although some compact cameras do use them as they provide greater storage. Typically, the SD card allows the entire camera to be smaller.