Seriously guys, ELI5 means "EXPLAIN IT LIKE I'M 5"
Here you go:
Sometimes bad people want to steal things you have, especially if it's worth a lot of money. Bitshares let's you put those things (such as gold, silver, oil, and your money) on the Internet where nobody can take them and bitshares also lets you trade those things with other people on the Internet where nobody can stop you from trading them. The best part is anybody in the world is free to do it.