H1-B is dual intent. After six years in the US as an H1B worker, you can become eligible to apply for a US Green Card, which will allow you to remain in the USA indefinitely. However due to the backlogs in priority dates for some categories, you could potentially be in H-1B status for 10-20 years while waiting for your priority date to become current. But you can keep renewing using AC21 provisions in the meantime.