what is single entry and double entry passport?

Answer 1

There's really no such thing as a single-entry or double-entry *passport*, but there are *visas* by those descriptions. They're actually quite the way they sound -- how many times are you allowed to enter the country within a fixed amount of time.

For example, Azerbaijan offers three different visas. One allows you to enter the country once and remain for 30 days. One allows you to enter the country twice during a 90-day period. The third allows any number of entries over a one-year period. China is probably the most common destination for Americans where the number of entries permitted by the Visa has to be addressed.

Answer 2

A single entry visa is exactly what it says... You're allowed to visit a country, and then leave and go home.

Double entry or multiple reentry visa will cost you more but you can do more with it. For example, you get a double entry visa to Japan You go there, and while you're there, decide to visit Korea for a couple of days. You get yourself the Korean visa, and have fun. After your Korea tour, you want to go back to Japan to finish your vacation. So, you go back on the same visa you were issued before (note now, that's your second entry into Japan). It may cost more, but lets you see more countries in a region. Just how often do you get to go to the Far East? (Hey I'm not counting myself.... I live here ;-))

Hope this explains everything.