Travel is the general movement of individuals between different distant geographic locations. Travel can be carried out by foot, vehicle, bicycle, plane, train, bus, boat, car or other mode, with or without personal luggage, to local or foreign destinations. The means of transport and modes of travel can vary significantly; for instance, a journey by bicycle may take only a few hours, while a four-hour cruise in a cruise ship may last the entire day. There are also regional types of travel such as sports travel, outdoor adventure travel, trekking travel and so on. The destinations and type of travel dictate the means of travel.

In compliance with the 21st Amendment to the Constitution of the United States, people traveling abroad have the right to travel abroad, except for people suffering from contagious diseases or infectious diseases that were imported into the United States and persons restricted from coming into the United States by orders of a federal court. Travel abroad is restricted within the United States by law and to some extent, travelers are prohibited from entering the United States by entering through Mexico or any other country of Mexico except through ports of entry designated as parts of the Mexico-versus Canada Border Crossing Program. Travellers may still travel to Canada via Mexico but must do so through an authorized port of entry.

On several occasions, U.S. citizens have traveled to other countries without obtaining a passport and then have returned to the United States without showing proof of citizenship. Such travel occurred during the early days of the republic when most men traveled by stagecoaches or horse-drawn carriage to their final destination. Today, most modern automobiles come equipped with internal combustion engines capable of powering a motor vehicle on cross-country trips. Traveling without a passport can result in penalties and fines or even jail time if the traveler is unable to prove his identity or eligibility for the travel. The lack of a valid travel document, regardless of its purpose, can result in serious problems for dual nationals or those traveling between countries or who are subject to immigration status verification.

Most U.S. citizens traveling to another foreign country will visit a tourist attraction, experience the local cuisine, shop at one of the many duty-free shops, visit the capital city or another important area of interest. They may also stay in a hotel, conduct business negotiations or even hold a business meeting while in the country. However, on short-term vacation rentals, most travelers are not required to show proof of identification or prove their citizenship prior to travel. Even when passport documentation is required, most overnight accommodations require proof of identity, even for rooms available through the short-term rental agencies. For travelers traveling to a foreign country that requires identification at the time of check in, some hotels and travel agencies allow travelers to use a photocopier provided by the hotel to create a temporary passport in lieu of a full-sized original.

Almost all travelers will experience difficulty filling out the appropriate visa requirements for their intended travel to another country. The types of visas available vary according to the country of travel and the status of the traveler. Some people traveling to another country can apply for an EAD or Employment Authorization Document, which is valid for up to six months. This type of visa can be required for agricultural workers, privately sponsored family members of the U.S. Armed Forces. Sponsorship of members of the U.S. Armed Forces requires that sponsorship be from a spouse or parent of a member who is deployed.

Although the majority of tourists to another country will be granted temporary residency or leave the country without inspection or restriction, some travelers may be denied entry due to certain behaviors. For example, if a foreign national contacts a family member or attempts to visit a country where he or she has family or other ties, they may be denied entry due to potential risks of re-entry. If a foreign national conspires to use a false passport to visit the United States, they may be denied entry. Some tourists who have been denied entry have used counterfeit passports to visit the country illegally.