The US Tourist Visa (B-1/B-2) is a non-immigrant US Visa. Its validity period ranges from 1 month to 10 years and allows single, double or multiples entries to the US. The period of stay which is a maximum of 6 months is recorded by the Customs and Border Protection officer. This is at the entry port on the Form I-94 of the Visa holder.
The validity period specifies the time period for which the Visa can be used to arrive in the US. The period of stay specifies the duration for which an individual can remain in the US after every single entry.
