Introduction: Majority of the people living in the United States of America are citizens. That is because they were born here, born outside the country to at least one US citizen, or naturalized. Rest of the people residing here are either green card holder (permanent residents) or non-immigrant visa holders.
The permanent residents can reside here permanently. They acquire their status either through a family member or through employment.
A non-immigrant on the other hand is a foreign national who has been admitted into the United States temporality for a specific purpose. Most common non-immigrant categories are A visa, B visas, H visas, and F visas.