A billionaire is a person with a net worth of at least one billion units of a given currency, usually of a major currency such as the United States dollar, euro, or pound sterling. It is a sub-category of the concept of the ultra high-net-worth individual. The American business magazine Forbes produces a global list of known U.S. dollar billionaires every year and updates an internet version of this list in real time. The American oil magnate John D. Rockefeller became the world's first confirmed U.S. dollar billionaire in 1916.
Black billionaires are individuals who are of predominantly African ancestry with a net worth of at least US$1 billion.
The Giving Pledge is a charitable campaign, founded by Bill Gates and Warren Buffett, to encourage wealthy people to contribute a majority of their wealth to philanthropic causes. As of June 2022, the pledge has had 236 signatories from 28 countries. Most of the signatories of the pledge are billionaires, and as of 2023, their pledges are estimated at a total of US$600 billion. However, there is no enforcement mechanism, and no restrictions on the charitable causes that signatories are allowed to support.
The World's Billionaires is an annual ranking of people who are billionaires, i.e., they are considered to have a net worth of US$1 billion or more, by the American business magazine Forbes. The list was first published in March 1987. The total net worth of each individual on the list is estimated and is cited in United States dollars, based on their documented assets and accounting for debt and other factors. Royalty and dictators whose wealth comes from their positions are excluded from these lists. This ranking is an index of the wealthiest documented individuals, excluding any ranking of those with wealth that is not able to be completely ascertained.
Poland 
United States