A work visa allows for the temporary employment in a host country. So if a foreign citizen hopes to gain employment in a country other than their home country they must apply for a work visa. Usually work visas are given for a specific period of time, often three years with possible extension to six depending on the circumstance. A work visa must be sponsored by a specific company in a country that the foreign citizen hopes to gain the employment through, and often times the visa is only good through that specific company. If the work arrangement ends for any reason, the work visa may become null and void resulting in the need to extend it, find alternate employment, or return to the home country. Work visas are more difficult to obtain than other visas and are usually good for a longer period of time.