"To form the base" means to establish a solid foundation or starting point for something. It is like creating a strong support or anchor that allows you to build or develop further. Full definition
But despite the spike in the number of new players coming to the genre, the big developers responsible for forming the basis of its origins have largely remained the same. (playstationlifestyle.net)
The story focuses on a magical spring which forms the basis of life in the world of Warriors All - Stars. (gearnuke.com)
Federal loans come in a number of forms based on the government program that they are managed under. (studentdebtwarriors.com)