What is the difference between "Standard Definition" and "High Definition"?

What is the difference between "Standard Definition" and "High Definition"?

Tim Smith (Camcorder Training Specialist) gives expert video advice on: What is an HDV camcorder and how does it work?; Can I watch my videos on a Hi-Def TV?; What equipment do I need to shoot HDV? and more...

If you haven't purchased a camcorder for a while, you're going to find that there's another new format of camcorder in town called high definition. So you've got to decide whether or not you want to shoot in standard definition or high definition. Let's talk about standard def for a second. Standard def really is a simple format designed for today's television sets but not the TVs of the future. They're going to deliver an image which will play on any television that's been made for years and they'll look very good. But standard def are not future proof. You're not going to be able to play these in high resolution later on when your television gets better. You'll still always be able to see them in standard def but if you're really in the market for a camera that's going to be future proof, you may want to consider one that will work with standard def as well as high definition.