Why is it? Edison really can be credited for 2 things. The light bulb and Direct Current. He didnt invent the lightbulb but improved upon 22 other ideas around the invention and figured out how to market it. And Tesla (who was his assistant at the time) actually had to help him get DC generators working after Edison promised him a large sum of money. To which Edison NEVER payed him and played it off as he was joking about it.

When Tesla came out with AC Edison payed kids in his neighborhood to round up animals for him to test on and he would electrocute them to prove that AC was dangerous and he even did the same to a elephant!

The difference between the two forms of power is DC would require a power plant every mile and had lower voltages. AC had higher voltages and could send electricity over great distances.

Tesla made patents on many ideas and inventions that were later used to create technology like radar, radio and x-ray but he get's 0 credit for any of it. With radar he actually pitched it to the navy during WW1, but guess who was head of the R&D for the navy and convince the Navy that it had little use? Edison.

Edison was not a inventor or innovator. He was a CEO that only cared about making money and knocking out the competition.

So why does the world celebrate him over Tesla?

Because he was a businessman and had money to build up a business with staff to invent things for him, and build up a reputation.

It kinda reminds me of an old swedish king. He kinda "forced" a good reputation on him by destroying the reputations of others, and historians thought he was nicey a goody for centuries, and then they realised he was actually a rather cruel bastard now and then and not the ideal national hero as previously believed.

Like I said before, Edison was the guy who wanted to profit more from the stuff. Tesla, who was ahead of his time, was also doomed with the fact that he was just a humble inventor who had obsessive tendencies and was more interested in tinkering. The Oatmeal has a really good comic about Tesla if you want an entertaining version of the internet's patron saint's story. The comic has tons of naughty words, so I can't link it. Just look up "Tesla Best Geek" and click on the first result.