Are the 7 wonders of the ancient world different than the modern ones, and why?

This is a very comprehensive question and sounds like homework, which AMHD does not provide to this extent. Have you tried a Google Search for the history of the 7 wonders of the world?

In addition to the medieval and modern world, there are also natural and underwater marvels. Culture has been making lists of the most spectacular man made structures and natural wonders for a long time. The seven ancient wonders are the Mausoleum at Halicarnassus, the Colossus of Rhodes, the Statue of Zeus at Olympia, Great Pyramid of Giza, Hanging Gardens, Temple of Artemis, and the Lighthouse of Alexandria.

Voting for the modern day 7 wonders is underway until 11/11/11.

As JudyKatTee suggested, a Google search generates plenty of helpful research material.