FSW-1 means Federal Skiller Worker under Category - 1 which means 1 year continuous work experience.
FSW-2 means Federal Skiller Worker under Category - 2 which means international student/worked minimum 1 year or more in Canada.
FSW-3 means Federal Skiller Worker under Category - 3 which means applications with AEO - Arranged employment offer in Canada. Applicants applying for immigration with AEO.