TSMC is the world's largest dedicated semiconductor foundry and a frequent market-cap leader.
Taiwan Semiconductor Manufacturing Company was founded in 1987 by Morris Chang in Hsinchu, Taiwan. Its defining business model was to manufacture chips designed by other companies rather than compete with customers by selling its own branded processors.
That foundry model allowed companies such as Apple, AMD, and Nvidia to concentrate on chip design while relying on TSMC's fabrication plants. Advanced process technologies and large production capacity made TSMC central to modern smartphones, data centers, graphics processors, and artificial-intelligence hardware.
TSMC is not the same kind of company as Intel or Samsung Electronics. Intel has historically designed and manufactured its own processors, while Samsung operates several businesses, including memory and foundry operations. “Foundry” describes contract semiconductor manufacturing, not a single chip product.