The word "millionaire" originated in England. It meant someone who had ₤1,000,000, one million pounds sterling. The United States borrowed the word and used it to mean $1,000,000, one million U.S. dollars. A millionaire was a very, very rich person. Now, it just means "someone rich." And it is commoner to use the word "billionaire." It is common to put the name of a kind of business in front of "millionaire" or "billionaire" to say how the money was earned. John D. Rockefeller was an oil billionaire. Donald Trump is a real estate billionaire. Carlos Slim is a telecom billionaire. Sulaiman Al Rajhi is a banking billionaire. Mark Zuckerberg made his money in an internet-business. The internet is computer-related. We could say: Mark Zuckerberg is an internet billionaire. We could also say, more generally: Mark Zuckerberg is a computer billionaire. When the word was coined, a million pounds meant someone was rich indeed. (At that time, a pound was worth about $5 and the British were scornful of Americans using the world "millionaire" for people who were only worth a million _dollars!_) As a result of inflation, $1,000,000 is not worth as much, and in the U.S. there are said to be about three million millionaires, but only about 500 billionaires.

He has become millionaire through computer related business or technology.