Contrast ratio: Contrast ratio is the difference between the brightest and darkest a TV can get. Static contrast ratio is a measurement that more closely reproduces real-world conditions. Dynamic contrast should only be used as a comparison within a brand.

Resolution: Refers to the number of pixels a device is able to assign to pictures. The more pixels you have, the sharper the picture will look.

Display type: Flat-panel TVs are available in plasma and LCD formats. Projection formats include DLP, SXRD (LCoS), CRT (tube) and LCD. Direct-view tube TVs are what most people consider “traditional” TVs.

Picture-in-picture: While there are many permutations of this feature, all indicate the ability to display more than one picture on the same screen. Most often, this requires a separate video source, such as a DVD player or tuner, to produce the second picture.

Screen size (diagonal): TV screens are measured diagonally, from corner to corner. HDTVs often look smaller than SDTVs with the same screen size because of the wider 16:9 aspect ratio.

Flat-panel technology: These can be either plasma or LCD. LCDs tend to be brighter, use less energy, and are all but immune to damage from static images. Plasma TVs typically cost less than comparably sized LCDs, offer better contrast, and have no issues with "motion blur."

Widescreen: Older displays are often referred to by a ratio: 4:3. I.e., they’re 4 parts wide and 3 parts tall. Today’s widescreen displays are 16:9, allowing us to see movies with narrower or even no black bars on the top and bottom of the picture.

Built-in tuner: Allows you to access and guide through TV channels without having to add an additional source. Without a built-in tuner, you will need to use your VCRs tuner to use the Picture-in-picture feature.

Maximum viewing angles: Because not all seats can be directly in front of the TV, how clearly you can see a TV from the side, or even when standing up, may be a factor in your home. The wider the viewing angle, the more clearly you’ll be able to see the TV from any position.

Comb filter: The job of the comb filter is to reduce “dot crawl” when displaying fine patterns. While comb filters can’t increase resolution, they do improve picture quality.

3:2 film correction: Video uses 30 full frames per second to create the illusion of motion, but film uses 24 frames per second. This disparity in frame rates can give movies an unnatural look. 3:2 correction compensates for this by adding the missing frames.

Light source: All TVs need light, and while it’s inherent in some technologies—like plasma, OLED, and cathode-ray tube—most require a separate light source. LCDs use fluorescent tubes or LEDs, while rear-projection TVs may use replaceable lamps, LEDs or even lasers.

Response time: Unlike plasma, LCD TVs have physical pixels that move to pass and block light. The ability to do this quickly (8 milliseconds and less) plays a part in reducing blurring when displaying fast motion.

Frame rate: Most TVs change or “refresh” the image on the screen 60 times per second, or at a rate of 60Hz. Some TVs, especially LCD flat panels, will refresh the image at a rate of 120Hz or higher, reducing the loss of clarity and resolution during fast action.

Auto volume correction: This feature automatically levels the volume coming from different program sources (i.e. programs, commercials, etc.).

Component video inputs: Capable of transmitting analog HD signals up to 1080p, a component connection separates video signals into three components, and is the best non-digital connection. A separate audio connection is required. Use this if HDMI isn’t available.

S-video inputs: This round connector carries video only, no audio, and while it will give you better picture quality than a Composite connection it is still limited to 480i resolution and cannot pass high-definition.

Composite inputs: A basic video connection commonly found on VCRs, game consoles and camcorders. All video information is combined, and a comb filter must be used by the display device to break the signal down into the component parts. Not recommended for best picture.

DVI (Digital Video Interface): This is a digital interface for connecting a video source, such as a DVD player, to an HDTV or HD monitor. DVI has the necessary bandwidth for uncompressed, HD digital video.

HDMI inputs: The number of HDMI inputs a TV has. The more inputs, the more components can be added to the system.

HDMI version: With every new version of HDMI come new capabilities, so later versions are may have improvements in picture, sound, or both. Example: ver. 1.3 is newer than ver. 1.1.

RF inputs: These are threaded posts that allow connection of RF cables, commonly used by cable, satellite and antenna. RF cables can be used to connect VCRs, cable boxes, and satellite receivers, but will not provide the best picture or sound.

PC compatible: Many TVs will have VGA or SVGA inputs that allow you to connect a PC, making it possible to view pictures and even videos on a large screen.

VGA/SVGA input: TVs with VGA/SVGA inputs are designed to work with a computer. These inputs can accept a signal from a PC and display a picture just as a computer monitor would.

IEEE inputs: These connectors, also known as FireWire and iLink, are designed for digital video, and make connecting a digital camcorder simple.

Memory card input: TVs with memory card slots can display pictures taken with digital cameras. This is a convenient way to share pictures with a group of people.

Energy Star compliant: Energy Star is a voluntary rating system established by the U.S. Department of Energy, the U.S. Environmental Protection Agency and electronics manufacturers. Energy Star labeled products surpass Federal energy efficiency standards by 20% or more.