Employment based (EB) is the name of one of two major categories of permanent resident visas. It's a term of art that doesn't include H1Bs. Given that what you quoted included the term EB I thought that was rather clear.
As for one ethnicity dominating the country -- the entire permanent resident visa program subject to the 7% rule is only 366,000 visas per year or .1% of the population. Even if all of those visas went only to Indians and Chinese the US would be in no danger of being "dominated" by one (or rather two) ethnicities. In any event on the family based side, which has a larger allocation than the employment based, it is Filipinos and Mexicans who face the longest waits, not Indians and Chinese. Finally the mapping between ethnicities and countries of birth is not one to one.
As for one ethnicity dominating the country -- the entire permanent resident visa program subject to the 7% rule is only 366,000 visas per year or .1% of the population. Even if all of those visas went only to Indians and Chinese the US would be in no danger of being "dominated" by one (or rather two) ethnicities. In any event on the family based side, which has a larger allocation than the employment based, it is Filipinos and Mexicans who face the longest waits, not Indians and Chinese. Finally the mapping between ethnicities and countries of birth is not one to one.