There are three types of cameras available: Point and Shoot or Compact, Prosumer and SLRs.

Point and shoot cameras also known as Compact cameras. They are generally small and less expensive as compared to the SLRs. They usually dont have a lot of controls. Point and shoot cameras are quite popular and easy to use. These do not require much effort or creativity on the part of the user. These are useful for sports and scenery shots. These cameras offer more features as compared to the Point and Shoot cameras.

SLRs offer many more features as compared to the Point and Shoot cameras. If you require taking scenery/sports shots an SLR is the right one for you.

Resolution is made up of building blocks called pixels. A million pixels together are called a mega pixel. Its on the resolution, which is composed of elements sensitive to sunlight, that the image is created. Each of these elements registers one of the points (called pixel) that create the picture.

The resolution of your digital camera determines what you can do with your photos, such as post them online or make prints and enlargements.

Higher the number of pixels the better quality of pictures will be and also gives larger size prints.

A non-electronic optical device used to view the image that is being shot is known as optical viewfinder. Optical viewfinders on compact cameras do not show exactly what is being shot because they are independent of the lens. The optical viewfinders on SLR cameras show exactly what is being shot because they are aimed through the lens.

The small window generally located at the top of the camera is the optical viewfinder. Look through the optical viewfinder to compose your shot; what you see framed there is what the camera will capture. Optical viewfinders are handy for the following reason: LCD screens are hard to see in bright light, so composing your shot is hard.

Using the optical viewfinder and turning off the LCD screen will make your batteries last considerably longer.

Colour Filter is a software that modifies digital images by altering the values or arrangement of selected image pixels.

A colour filter is an optical attachment placed on the front of the lens. It is used to correct color or enhance an image by absorbing parts of the visible light spectrum or create special effects through prisms and other optical enhancements.

It enhances the quality of the images taken and gives better images.

Aperture is the opening in a lens through which light passes to the image sensor to create an image.

Aperture size is usually calibrated in f-stops. The higher the f number the smaller is the aperture. The common f-stops are f/2, f/2.8, f/4, f/5.6, f/8 etc.

The quality of the image depends upon the aperture range and shutter speed of the camera. The larger the f number, the smaller the lens opening and hence less light will enter into the camera.

Shutter priority is an exposure mode that lets you select the desired shutter speed. Shutter Speed is measured in seconds. It is the time for which the camera exposes the sensor to the light being let in by the aperture setting.

A shutter consists of blade, a curtain, plate, or some other movable cover in a camera that controls the time during which light reaches the sensor. Many point and shoot cameras have fixed shutter speeds. Single Lens Reflex (SLR) cameras offer a greater control over the shutter speed. If you use a very slow shutter speed (about 1/8 sec) you will not be able to hold the camera in your hand and shoot the subject clearly. The image thus obtained will get blurred.

The two types of sensors are CCD and CMOS. CCD - Charged Coupled Device sensor is a light sensitive chip used for image gathering. CMOS - Complementary Metal Oxide Semiconductor is another type of image sensor found in a digital camera. Pixel sensitivity is lower than the CCD sensors and usually has more noise in the imaging device.

CCD is the most common form of photosensitive cells used to convert incoming light into electrical signals in digital cameras. In their normal condition these are greyscale devices. To create colour, a colour pattern is laid down on the sensor pixels, using RGBG color mask. (Red, Green, Blue, and Green) The extra Green is used to create contrast in the image. The CCD Pixels gather the colour from the light and pass it to the shift register for storage.

A digital image sensor converts light into electrical signals, which are then converted into an image inside the camera using the cameras image processor.

Digital zoom enlarges the subject within an image, while reducing the resolution of an image.

A digital zoom is software inside the camera that enlarges subject in an image. Due to the doubling of pixels the image begins to become fuzzier and fuzzier as you enlarge.

Optical zoom is a feature that alters a cameras focal length, filling more of the frame within the subject.

An optical zoom lens actually moves in and out of the camera to get wide-angle, telephoto and macro (close-up) shots. Unlike a digital zoom, an optical zoom will not reduce the resolution of your photos. These days, a 3x optical zoom is pretty standard, with some models going up to 10x or even 12x.

Optical zoom helps you to concentrate on the subject of the image. It is more useful in taking pictures of flowers, animals, insects etc. It also brings a faraway object nearer and hence is more useful in taking pictures of flora and fauna.

Some cameras allow the user some creativity in terms of the kind of picture modes in different environments, such as Portrait, Landscape, Night Scene and Sport etc.

Shooting modes are the amount of controls you have in choosing how your digital camera captures an image. They include automatic mode, portrait mode, macro mode, landscape mode, sports mode, night mode, movie mode etc.

The shooting modes enhance the quality of images when shot as per the situation. For example, the Portrait mode is used especially where you wish that only the subject that is being shot appears clearly, and the background gets slightly blurred so as not to distract attention.

Macro mode allows a digital camera to take close-up pictures of small objects like fingernail art, flowers, stamps, insects, etc. Macro mode is an absolute must have for shooting close up images.

The Macro mode enables auto focusing as close as 2cm away from the object. Many cameras offer a macro mode capable of recording images as close as 1cm also.

It is useful for taking close-ups of flowers, insects and other small subjects.

Centre Weighted Metering measures the brightness of the light at the centre of the frame, as well as around the centre, to calculate the correct exposure for the image.

This makes it possible to capture the image with the right exposure even when the subject at the centre is bright and the background is dark.

Centre Weighted Metering averages the exposure of the entire frame but gives extra weight to the object in the centre and is ideal for taking portraits.

Multi Metering means when the camera measures the light intensity in several points in the scene, and then combines the results to find the settings for the best exposure.

This makes it possible to capture the image with the right exposure when the whole subject bright.

Multi Metering averages the exposure of the entire frame which is to be captured.

Spot Metering measures a narrow zone at the centre to determine the exposure level.

This is useful for highlighting the subject and enhancing the visual impact, and also for capturing the details in a highlighted section.

Spot metering allows only a small area of the whole frame to be metered and the exposure of the rest of the frame is ignored. It is the most useful for backlit, macro and moon shots.

The rechargeable batteries are either of NiMh (Nickel Metal Hydride) or Li-Ion (Lithium Ion) type. The NiMh batteries recharge in 1 to 2 hours while the Li-Ion batteries recharge in 3 to 5 hours.

The Li-Ion batteries hold charge for a longer time, especially with digital cameras that use more battery power as compared to NiMh batteries.

It denotes the number of images that can be captured after one battery charge.

Bluetooth is a short range wireless technology that connects electronic devices, including cell phones, printers, digital cameras or palm top computers. It is designed to exchange data at speeds up to 720 kbit/s and at ranges up to 10 metres.

Images can be transferred and saved from a bluetooth enabled camera to the computer or images can be printed using a bluetooth enabled printer.

It is a wireless technology which replaces the connecting cables. The key features are low cost and low power.

WiFi stands for Wireless Fidelity. It allows wireless access to the computer or camera without the use of the cables.

WiFi cameras use wireless computer networking technology to connect to a wireless network. If you have a wireless network at home or work, you can connect to it with a wireless-enabled digital camera and download your photos to a computer without any cables.

It helps in transferring the images from a digital camera to a computer or a printer without the use of cables. This means easier image downloads, printing and sharing of photos without using a memory card reader or a USB cable.

PictBridge is a software in many digital cameras, camcorders and printers that allows them to communicate with one another without needing a computer to translate.

Take any PictBridge-enabled digital camera and connect it directly to any PictBridge-enabled printer using a USB cable to get great photos, without needing a computer to play in the middle.

PictBridge makes printing the images very easy.

This determines the operating system on which the camera works. Most of the digital cameras work on Windows or Macintosh software. Types of Operating Systems are Windows 98, Windows 2000, Windows XP and Windows Vista.

Digital Cameras save images on a removable device like SD and MMC card.

Digital cameras store the photos they take to some kind of memory. A handful have high built-in memory, while a few record photos on SD cards, MMCs, etc. However, in general digital cameras store photos to some kind of removable media. The memory cards are the size of a postage stamp and weigh about 2 grams. They come in various sizes like 256 MB, 512 MB, 1 GB, 2 GB and 4 GB.

The memory card stores the images and video recordings as the internal memory of most of the cameras is less.

It is the format in which digital images are stored in the digital camera.

There are numerous ways to store an image, and the most popular are jpeg, gif, tiff, bitmap and the more complicated raw files. You can identify which format is used by looking at the end of the file name after the period. For example, picture.jpg is a jpeg file. The most widely used is the jpeg format.

The image format stores all the images in the camera.

Images can be captured by applying special effects to the images. Special Effects differ from one manufacturer to another. Some types of special effects are High color, Natural color, Low color, Sepia, Black and White, Vivid, Neutral, Positive, Black and White, Darker Skin Tone, Lighter Skin Tone

The continuous shots feature helps to shoot consecutive images until the memory is full.

Once the internal memory is full the digital camera transfers the images from the internal memory to the memory card.

The correction of the appearance of a red eye applied on a picture-by-picture basis is called as red eye reduction.

This feature causes the flash to emit a burst of light before the photograph is taken, which causes the pupils of your subject to narrow. This reduces the chance that you will see a lot of red eye in your photograph, although it will not eliminate it completely.

Many digital cameras let you record short clips of highly compressed, low-resolution video, either as an MPEG movie. (320 x 240 is a common resolution). Some record audio too. Although these low-resolution movie modes cannot replace the high-quality video you get from a digital camcorder, they can be another fun way to capture faces or events.

Exposure Compensation Value denotes all combinations of camera shutter speed and relative aperture that give the same exposure.

The exposure time (shutter speed) determines the amount of motion blur and the relative aperture determines the depth of field.

Some cameras with high optical zooms such as 6x or higher come with an image stabilizing feature. It automatically eliminates any camera shake like the slight jiggling motion that can result as you hold the camera thus helping you ensure a crisp, sharp photo.

The image stabilization function prevents blur by flexibly shifting the lens itself and bending the light axis whenever the built-in sensor detects camera shake.

The image stabilizer improves the quality of the image by preventing blur images due to camera shake.