One thing many non-Americans find concerning is our “at-will” employment concept. In the U.S. (except for the state of Montana), an employer can let an employee go without warning, and an employee can leave a job on short notice as well. No reason needs to be given for a firing, and a company has the right to fire at any time.
The United States is one of the few countries in the world that has this policy. Companies in a lot of other countries have to give a just cause for firing someone, or else provide feedback and warnings for an errant employee so they can improve. Each country has a different approach to worker’s rights, and the U.S. is no exception.