In us navy what does Ensign JG mean?

In the U.S. Navy, "Ensign JG" refers to the rank of Ensign (O-1) and "JG" stands for "Junior Grade." However, the term "JG" is more commonly used in the context of the U.S. Coast Guard and refers to "Junior Grade" officers. In the Navy, an Ensign is the entry-level rank for commissioned officers, and they typically hold this rank for their first two years before being promoted to Lieutenant Junior Grade (O-2).