Apple CEO Steve Jobs says the iPhone 4, which debuted on Monday, is the “biggest leap forward” the iPhone has made since it was introduced in 2007. The newly announced phone has “one of the most beautiful designs you’ve ever seen,” Jobs said at a tech conference in San Francisco.

“This is without a doubt the most precise thing and one of the most beautiful things we’ve ever made.”

But besides being “beautiful,” what actually makes this iPhone different? After attending the unveiling and talking with analysts and bloggers, here’s our quick list of 10 things you should know about the iPhone 4, which goes on sale June 24, and costs between $199 and $299. Let us know if you have more questions and feel free to leave thoughts of your own in the comments section at the bottom of this story.

Sharper screen

In his Monday keynote address at Apple’s Worldwide Developers Conference, Jobs sounded more excited about the iPhone 4′s new screen than anything else. With 326 pixels per inch — four times that of previous Apple phones — Jobs says the iPhone 4′s “retina display” screen is years ahead of anything else on the market. “Text looks like you’ve seen it in a fine printed book — unlike you’ve ever seen on an electronic display before,” he said. “Once you’ve used a retina display you can’t go back.”

Gyroscope

“These phones are getting more and more intelligent about the world around them,” Jobs said. That’s true of the iPhone 4, which has five sensors, including a gyroscope.

What does that mean for users? Probably cooler games and apps. The iPhone 4′s internal gyroscope can sense motion on six axes. On Monday, Jobs showed a demo where he pivoted in a circle, and the stack of blocks in an app spun with him. The phone is basically more aware of where it is in the world, in relation to gravity, than it was before. It’s hard to say exactly what app developers will do with this, but likely something.

Thickness

The iPhone 4 will be the thinnest smartphone on the market, Jobs says. At 9.3 millimeters (0.37 inches) thick, it is 24 percent thinner than the previous iPhone model, the 3GS, he said.

“I don’t think there’s another consumer product like this,” he said. “When you hold it in your hand it’s unbelievable.” The iPhone 4′s screen remains the same size as before, 3.5 inches when measured diagonally. That makes it smaller than some Android phones, which are its main competitors. But that may not be a good thing. As people watch more video on their phones, they’re demanding larger screens, some analysts say.

Camera flash

In what’s largely seen as a catch-up move, Apple added an LED flash to the iPhone 4′s camera, which lets mobile photographers shoot photos and video more easily at night.