What does the American green card ir7 mean?

There are many kinds of green cards in America. Among the IR series known to immigrants from Australia and Shenzhen, 10, ranging from IR0 to IR9, is as follows:

IR0: Parents of American citizens. Parents of American citizens.

IR 1: the spouse of an American citizen. Spouses of American citizens.

IR2: Children of American citizens. Children of American citizens (for applications outside the United States).

IR3: Orphans adopted by American citizens abroad.

IR4: Orphans adopted by American citizens.

IR5: Parents of American citizens.

IR6: The spouse of an American citizen.

IR7: Children of American citizens. (Application for Adjustment of Identity in the United States)

IR8: Orphans adopted by American citizens abroad.

IR9: Orphans adopted by American citizens.

Among them, the American green card IR7 refers to the children of American citizens.