In China, they are known as nongmingong, meaning "farmers-turned-workers", a term that likely means more in Chinese than it does in English.
And now this important segment of the Chinese workforce have come to world prominence, thanks to Time magazine naming them runners-up to Ben Bernanke in its latest Person of the Year awards.
While the US Federal Reserve chairman scooped the top honor, the fact that the nongmingong were singled out shows their importance on the global stage.
Leaving behind families and homes to migrate to China's cities, they take on largely manual work and are among the country's lowest-paid workers.
They often go about their work in relative obscurity, despite numbering around 200 million.
But while the nongmingong will garner a good deal of attention, Bernanke will be on the cover of the magazine, in recognition of his maneuvering of US monetary policy that helped steer the world's largest economy out of the financial crisis.
The Chinese workers ranked second were the only group named. The magazine described them as "an increasingly influential group in one of the world's most powerful economies."
This year, China's year-on-year gross domestic product (GDP) growth is set to exceed 8 percent. The growth rate means it will contribute about 20 percent of this year's global economic growth, Cheng Siwei, former vice-chairman of the Standing Committee of the National People's Congress, said last month.
Analysts said the country's nongmingong were an important part of the economic miracle in recent years.
"This group will have a great bearing on China's future development," said Chen Gong, chief economist and chairman of Anbound Group, a Beijing-based consulting firm.
"More importantly, they are linking the cities and the rural areas, playing a role in bridging the gap between the two," he said.
The important role of migrant workers in the Chinese economy, however, accentuates the fact that China still relies on low-technology manufacturing to support its economic development, said Zhong Jiyin, an economist with the Institute of Economics of the Chinese Academy of Social Sciences (CASS).
Time magazine also listed China's central bank governor Zhou Xiaochuan on its list of People Who Mattered.