What's the difference between Form A and Form B of American immigrants? How is the timetable worked out?

The difference between Form A and Form B of American immigrants lies in the different types of immigrants. The timetable is calculated according to the immigration bill and the application situation. Specifically, scheduling refers to the time for immigrant applicants to wait for an immigrant visa of a specific immigrant category. American immigration law stipulates that the number of immigrant visas for each immigrant category is limited, and each country or region can only allocate a certain number of immigrant visa places every year. When the number of applicants exceeds the available visa quota, the Immigration Bureau will allocate a timetable for these applicants. Schedule A is applicable to family security, category I employment (EB- 1) and special labor security (occupations with specific skills or labor shortage); Schedule b applies to workers sponsored by employers (EB-2 and EB-3). Each timetable calculates the time according to the immigration category, the country or region of application and the date of application. For Schedule A, applicants usually need to wait for a shorter time because there are more visa places in the Schedule. However, the number of Schedule B visas is limited, and applicants often have to wait longer. It should be noted that the timetable only gives an approximate waiting time range, and the actual waiting time may change due to various factors, including the demand of immigration categories, the change of the number of applicants and the processing speed of the immigration bureau. To sum up, the difference between American immigration schedules A and B lies in the different types of immigrants, and the schedule is calculated according to the immigration law and the application situation. The waiting time of schedule A is usually short, while the waiting time of schedule B may be long.