No Visa Requirements

Some countries do not require a visa at all but instead may request proof of financial solvency or property at home. The Bahamas is one such country.

Visa Waivers

Not all countries are created equal. Some countries issue visa waivers for citizens of a particular country. For example, the United States has a visa-waiver agreement that allows citizens of Canada to travel with only a passport.

Length of Stay

In many countries, whether or not a traveler requires a passport depends upon the length of his stay. The standard is under 30 days, during which a trip for pleasure may not require the visa. Countries with such a policy include, but aren't limited to, the United Arab Emirates, Canada (a stay of up to 180 days is allowed), France, the United Kingdom and Japan (up to 90 days).

Reason for Visit

Many countries require people traveling for work, study, diplomatic or immigration reasons to obtain a visa, regardless of the length of stay or country of citizenship.

Visa Application

Visa applications are usually handled at embassies and consulates within the traveler's country. The fees vary, as do the processing times. Occasionally, some countries allow visas to be processed upon arrival at the port.

Source:

U.S. Department of State