A US tourist visa entitles the holder to travel to the United States of America for a limited amount of time; this can be as a tourist or to visit friends and relatives. The main type of tourist/visitor visa the US use is the B2 visa.
The B2 visa is not a route to gain permanent residence in the US and is only intended for use with tourism, visiting friends and relatives, for health reasons and short study courses. For people seeking permanent residence a US Green Card or Permanent Resident Card must be applied for.
A B2 visa is usually approved for a period of between 1 and 10 years, and during this period the visa holder is entitled to enter the US multiple times, as long as it is used in accordance with the B2 visas regulations.
Each of the B2 visa holders visits to the US will be limited to no more than six months; this can be extended by an extra six months, but the visa holder must show that their visit is a temporary one and that they intend to return to their country. A B2 visa holder is not allowed to work in the US or entitled to any employment rights.