The B-2 visitor visa is also referred to as the "tourist" visa. Foreign nationals who wish to enter the United States for recreation and pleasure or for medical treatment often use it.
he has to apply in the country of which he is a citizen: eg: a German citizen living in Denmark must apply at the German consolate to obtain a Visa
yes
Depends what visa and what country
Of course not. You cannot work in Singapore with a visitor's visa. This would be illegal. You have to apply for a Singapore work visa.
A B1 visa is a non-immigrant visa that allows individuals to enter the United States for business purposes, such as attending meetings, conferences, or training sessions. It does not permit the holder to engage in paid work in the U.S.
Nobody can work in the visa on a visitor visa. Short duration courses like cookery class that will not add any credits to a course can be attended using a visitor visa. But working in the US, that will enable you to draw salary is not allowed on a visitor visa.
Depends what visa and what country
Determine your visa category: Identify the appropriate immigrant visa category, such as family-sponsored, employment-based, or diversity visa (DV) lottery.
The non-immigrant visa number shows up in red ink on the lower-right side of the K-1 Visa.
The "tourist" visa for US is also referred to as the B-2 visitor visa. For recreation and pleasure or for medical treatment often foreign nationals who wish to enter the United States use it. Careful preparation is required for the process of applying for a B2 visa (visitor visa). It is important to present an error free application the first time, since it becomes very difficult, if not impossible, to successfully obtain a B-2 Visa (visitor visa) once an individual has been previously denied a visa. Errors on the B2 visa application process can make one permanently ineligible to visit the U.S. pursuant to a valid visa.
A Immigrant needs a Visa, Passport and a place to stay. :)
If for some reason you are stopped by border security, your visitor's visa will not take precedence.