What's the difference between American visas L1a and L1b?

L1 visa is a non-immigrant visa, and like H1B work visa, it has a dual intention visa, that is, it is a visa with an immigrant tendency.

there are two types of p>L1 visas, L1A and L1B.

L-1A is a visa issued to the managers or supervisors of multinational companies going to branches in the United States, and their residence period in the United States can be up to seven years.

L-1B is a visa for professionals, and the maximum residence period in the United States can be five years. If its professionals are promoted to managers or supervisors in the United States, their residence period can also be promoted to seven years.