Foundry vs fabless
A foundry manufactures chips designed by other companies; a fabless firm designs chips and outsources all of its manufacturing.
Foundries, such as TSMC, Samsung Foundry, Intel Foundry and GlobalFoundries, sell wafer manufacturing and often packaging to chip designers. Fabless companies, such as Nvidia, AMD and Broadcom, design chips and buy the manufacturing from foundries. Some companies, such as Intel historically, both design and manufacture their own chips.
Foundry revenue depends on customer volumes, the nodes they use and their capacity utilization. Fabless margins depend on pricing power and on securing enough foundry capacity at the right node. A shortage at the foundry can limit a fabless company's shipments even when demand is strong.
Worked example (illustrative numbers, not real data): a fabless company sells a chip for 500 dollars and pays 150 dollars per unit for wafers and packaging. Before design, software and overhead costs, its gross margin on that chip is 70 percent.