Apple was the first publicly traded company to reach a $2 trillion market value during the 2020 market-cap milestones.
Apple crossed the level in August 2020, about two years after its first $1 trillion milestone. The company benefited from the scale of its iPhone installed base, expansion of services, and strong investor demand for large technology stocks.
Market capitalization is a simple multiplication: share price times shares outstanding. It can therefore change even when a company does not issue new products on that day. Stock splits can also alter the quoted share price without changing the underlying value of shareholders' combined ownership.
Apple's later $3 trillion milestone continued this sequence, although market leadership and exact valuations have shifted repeatedly as share prices changed.