Immigration Law is very deep and wide. It can be divided into five to six main areas for the purpose of simplicity: Visas: Non-immigrant and Immigrant. Immigrant visas can still be categorized under: Family based, Employment based, Investment/ business based, Removal Defense and finally Naturalization/citizenship.

Non-immigrant Visas

A - Diplomatic employees and their households
B - Business visitors (B-1) and Visitors for Pleasure (B-2)
C - Transit visa
D - Crew member
E - Treaty Visa (E-1 Treaty Trader) (E-2 Treaty Investor)
F - Students
G - Employees of International Organizations
H - Temporary Workers (minimum of a university degree required)
I - Representatives of international media
J - Exchange visitors
K - Fiancés
L - Intracompany transferees
M - Language and vocational students
N - NATO employees
O - Extraordinary ability aliens
P - Athletes, entertainment groups
Q - Cultural exchange visitors
R - Religious workers
S - Criminal informants

The major categories relate to Visitor/Tourist visas-B1/B2, the Students and their dependent visas of F or M, the Treaty Trader/ Investor visas of E-1 & E-2, the Fiancé visas (K-1/K-2), The Religious visa (R-1/R-2) and the Specialty occupation visas in the H-1, H-2 categories.