Valid passports verify a person's identity, and are shown at border crossing from one country to another. Passports also serve as a form of internationally recognized governmental documentation.
I-94 / I-95
An I-94 document is required by all non-immigrant visa holders entering the United States. This document is of surprising importance. Under immigration law, a person who is admitted by a border official is treated very differently from someone who evades border inspection (entry without inspection or EWI, as it is commonly called). Save this document. The I-95 document is reserved for crewmembers of aircrafts or sea vessels upon U.S. port arrival.
Border Crossing Cards
B1 and B2 visas are also called border crossing cards. These cards allow you to travel to and from the United States until the expiration date noted on the card. Expiration usually occurs about ten years after the date of issuance.
A visa is the government's permission to allow you to remain within the United States legally. Visas may or may not permit employment, and generally last for a finite period of time.
Citizens of some countries, such as Australia and Sweden, may be eligible for the visa waiver program. An actual visa is unnecessary; however, there are still restrictions on employment and a time limit to be aware of.
This document allows individuals who do not hold permanent residency within the United States to return to the States after an extended trip outside the country. This is different than a reentry permit.
This document is also known as a green card or alien registration card. This is issued to you upon becoming a lawful permanent residence.
Form I-131 is an application for travel that allows you to reenter the United States after travel abroad if you are a permanent resident holding a green card.