The majority of people are 'at-will'. Which is not the same as a contractor, but for the purpose of your question it may as well be. In some cases you may have

The majority of people are 'at-will'. Which is not the same as a contractor, but for the purpose of your question it may as well be. In some cases you may have severance pay defined by the terms of the employer, but that became pretty rare as something that would be promised after the 2008 recession. It still happens but not like it used to. Generally speaking you are 'at will' in the United states, so you can be let go for any reason that is not explicitly illegal to do so for (i.e. race, old age, etc.) You could theoretically get let go because the owner decided 'I found a penny on the ground today and I decided it was a sign to fire you'. On one hand this is because, inversely speaking, you, again, typically allowed to quit at any moment for any reason you want. Including getting another job. This does however handwave away the asymmetry in finding a replacement for an employee versus finding a new employer. It's also concerning in this modern age where some Sandwich shops try to get line workers to sign noncompetes.