A developed country or "more developed country" (MDC), is a country with an economy with high growth and security. Most commonly the criteria for evaluating the degree of development is to look at gross domestic product (GDP), the per capita income, level of industrialization, amount of widespread infrastructure and general standard of living. Which criteria, and which countries are classified as being developed, is a contentious issue. According to the International Monetary Fund, advanced economies comprise 65.8% of global nominal GDP and 52.1% of global GDP (PPP) in 2010. In 2011, the ten largest advanced economies by either nominal GDP or GDP (PPP) were: the United States, Japan, Germany, France, the United Kingdom, Italy, Canada, Spain, South Korea and Australia.

Countries not fitting such definitions are classified as developing countries or undeveloped countries.

Terms similar to "developed country" include "advanced country", "industrialized country", "'more developed country" (MDC), "more economically developed country" (MEDC), "Global North country", "first world country", and "post-industrial country". The term industrialized country may be somewhat ambiguous, as industrialization is an ongoing process that is hard to define. The term MEDC is one used by modern geographers to specifically describe the status of the countries referred to: more economically developed. The first industrialized country was the United Kingdom, followed by Belgium. And later it spread further to Germany, United States, France and other Western European countries. According to some economists such as Jeffrey Sachs, however, the current divide between the developed and developing world is largely a phenomenon of the 20th century.

William Henry "Bill" Gates III (born October 28, 1955 in Seattle, Washington) is an American business magnate, computer programmer and philanthropist. Gates is the former chief executive officer (CEO) and current chairman of Microsoft, the world’s largest personal-computer software company he co-founded with Paul Allen. He is consistently ranked among the world's wealthiest people and was the wealthiest overall from 1995 to 2009, excluding 2008, when he was ranked third; in 2011 he was the wealthiest American and the second wealthiest person. During his career at Microsoft, Gates held the positions of CEO and chief software architect, and remains the largest individual shareholder, with 6.4 percent of the common stock. He has also authored or co-authored several books.

Gates is one of the best-known entrepreneurs of the personal computer revolution. Gates has been criticized for his business tactics, which have been considered anti-competitive, an opinion which has in some cases been upheld by the courts. In the later stages of his career, Gates has pursued a number of philanthropic endeavors, donating large amounts of money to various charitable organizations and scientific research programs through the Bill & Melinda Gates Foundation, established in 2000.