A work permit is a document that legally allows a non-citizen of the USA to work for a country based in the country while also residing in the country. The work permit is also known as an Employment Authorization Document, and it proves that the individual is legally eligible to work in the country.
In order to obtain a work permit, both the employer and the potential employee have roles to play in sorting out the immigration issues surrounding the employment. Both parties also have the responsibility of showing that the employment will be legal.
For a work permit to be awarded, the employee has to prove that they are authorized to work in the country, and the employers are also required to provide information about the identity and eligibility for all foreign staff. Foreign workers who may be permitted to work in the country include lawful permanent residents, aliens authorized to work in the country, non-citizen nationals of the United States, temporary non-immigrant workers, permanent immigrant workers and students and exchange visitors. The latter group can only work under certain circumstances, and will often need to obtain authorization from a school official before being permitted to join the workforce.
In summary, in order to obtain a work permit in the United States, you first have to obtain legal entry into the country, and also have a legal basis for staying within the country either as a permanent or temporary resident. After this, one can then apply for the Employment Authorization Document. If eligible, one would receive the EAD card which would allow them to work in the country for a year, after which they would need to renew the document.