For consumer digital cameras, sensor sizes can range from 0.4 to around 8 mega pixels. The cost of the camera is closely related to this value, due to the complexity of the lenses and amount of processing power needed. For photos to look acceptable on screen or on the Web, a 1 mega pixel camera may be fine. If you frequently crop images or make big enlargements, you will need more mega pixels. Don't forget, the larger the sensor, the larger the output files, meaning that pictures will need more storage space and take longer to display or send to other people.
Good color is important to making attractive pictures.
Good auto-exposure controls and accurate white point processing will also improve results. Check magazine and online reviews of the model that you want to buy. Picture-taking speed Film cameras respond almost instantly when you press the shutter release button. Digital cameras do not. The delay time varies among digital cameras, ranging from a fraction of a second to over a second in some cases.