A visa is approval from one country, usually in the form of a stamp on a passport, authorizing the holder to enter or pass through that country. When a country issues a waiver, an individual is exempt from presenting a visa for entry.

Visa Waivers

Some countries issue visa waivers for citizens of a particular country only. For example, the United States has a Visa Waiver Program that allows citizens of 35 countries to visit without the issuance of a pre-approved visa.

Length of Stay

In many countries, whether or not a traveler requires a visa depends upon the length of his stay. The standard is under 30 days, during which a traveler visiting for pleasure may not require a 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).

No Visa Requirements

Some countries do not require a visa at all but instead may request proof of financial solvency, property or some other tangible attachment to one's native land. The Bahamas is one such country.

Reason for Visit

Even if an individual appears to meet the requirements of a visa waiver, additional stipulations may disqualify her. For example, 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. For these pursuits, visa waivers are rarely issued.

No Visa Waivers

Many countries do not normally issue visa waivers. Though the list is lengthy, such countries include China, Brazil, India, Bolivia, Ghana and Russia.

Source:

U.S. Department of State