What is the richest company in the world?

Could you please elaborate on the question, "What is the richest company in the world?"? I'm curious to know how we determine the wealthiest corporation globally. Is it based on market capitalization, annual revenue, or net worth? Also, does the ranking change frequently, or are there certain companies that consistently hold the top spot? Moreover, are there any industries that tend to have richer companies, or is it more diverse across different sectors? Finally, what are the factors that contribute to a company's wealth, and how do they impact its ranking? Thank you for clarifying these points.