What is the difference between a HDTV and LCD?

High-definition television (or HDTV) is a digital television broadcasting system with higher resolution than traditional television systems
The two most popular types are Liquid-crystal display televisions (LCD TV)  and Plasma display panel (PDP) a type of flat panel display common to large TV displays (32" inches or larger).
  LCD Advantages

• No burn-in of static images.
• Cooler running temperature.
• No high altitude use issues.
• Increased image brightness over Plasma.
• Lighter weight (when comparing same screen sizes) than Plasma counterparts.

Plasma Advantages

• Larger screen size availability.
• Better contrast ratio and ability to render deeper blacks.
• Better color accuracy and saturation.
• Better motion tracking (little or no motion lag in fast moving images).

  LCD Disadvantages

• Lower contrast ratio, not as good with deep blacks.
• Not as good at tracking fast moving objects and a lag may be exhibit - However, this is improving with the recent implementation of 120Hz screen refresh rates and 240Hz processing in higher-end LCD sets.
• Not as common in large screen sizes above 42-inches as Plasma. However, the number is growing fast, with 46 and 47-inch screen sizes becoming more common, and some LCD sets having a screen size as large as 65-inches
• Although LCD televisions do not suffer from burn-in susceptibility, it is possible that individual pixels on an LCD televisions can burn out, causing small, visible, black or white dots to appear on the screen. Individual pixels cannot be repaired,
• LCD televisions are typically more expensive than equivalent-sized Plasma televisions (although this is changing), especially when comparing EDTV Plasmas to HDTV-LCD Televisions.

Plasma Disadvantages

• More susceptible to burn-in of static images.
• Generate more heat than LCDs, due to the need to light of phosphors to create the images.
• Does not perform as well at higher altitudes.
• Potentially shorter display life span - this used to be the case. Early Plasmas had 30,000 hours or 8 hrs of viewing a day for 9 years, which was less than LCD. However, screen life span has now improved and 60,000 hour life span rating are now common, with some sets rated as high as 100,000 hours, due to technology improvements

HD TV is a set of standards for high definition television signals,1080 line and 720 line resolutions. The signal format is completelyindependant of the display device and can be shown on any monitorcapable of displaying HD signals.LCD is a type of display (CRT and plasma being the other twocommonly available). An LCD television will either be standarddefinition or high definition and the manual will say if it is capableof showing HD signals.

For a short answer the difference between a new HD LCD monitor and a regular LCD monitoris the screen resolution. The HD monitor has a high pixel and screenrate. Oh, and of course the price. HDTV tv's are pricer than the LCD versions.
Have fun tv watching!

LCD isShort for liquid crystal display, a type of display used in digital watches and many portable computers. LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light.
HDTV is high-definition television: a television system that has more than the usual number of lines per frame so its pictures show more detail.

A LCD can be an HDTV.