All visas fall within two broad categories: non-immigrant and immigrant.
Non-immigrant visas are given to individuals who intend to reside temporarily in the United States. The position they fill may be permanent, but they must be in it temporarily. The vast majority of the UW’s international faculty and staff are here in some non-immigrant category.
Immigrant visas are for those who intend to reside permanently in the United States and have an offer of permanent employment. Non-immigrant visas require considerably less documentation and processing time.