Series A, B, C Funding: How It Works
A startup with a brilliant business idea is aiming to get its operations up and running. From humble beginnings, the company proves the worthiness of its model and products, steadily growing thanks to the generosity of friends, family and the founders' own financial resources.
https://www.investopedia.com/articles/personal-finance/102015/series-b-c-funding-what-it-all-means-and-how-it-works.asp