Q. Explain working of Digital camera?

A Digital camera is a camera which captures and stores still images and video (Digital Video Cameras) as digital data in place of on photographic film. The first digital cameras became available in early 1990s. Because the images are in digital form they can be afterwards fed to a computer or printed on a printer. 

Like a conventional camera a digital camera has a series of lenses that focus light to create an image of a scene.  Howeverin place of this light hitting a piece of film, camera focuses it on to a semiconductor device which records light electronically. An in-built computer then breakdown this electronic information in digital data.

This semiconductor device is known as an Image sensor and converts light into electrical charges. There are two main kinds of Image sensors: CCD and CMOS. CCD signifies Charge coupled devices and is the more powerful and more popular kind of sensor. CMOS signifies Complementary Metal oxide semiconductor and this type of technology is now only employed in some lower end cameras. While CMOS sensors may improve and become more popular in the future, they perhaps won't replace CCD sensors in higher-end digital cameras.

Briefly the CCD is a collection of tiny light-sensitive diodes known as photo sitesthat convert photons (light) in electrons (electrical charge). Every photo site is correspondingly sensitive to light - the brighter the light which hits a single photo site the greater the electrical charge that will gather at that site.   

A digital Camera is also considered by its resolution (such as printers andmonitors) that is measured in pixels.  The higher the resolution the more detail is available in the image.