The I-130 immediate relative petition allows a U.S. citizen to sponsor his or her spouse to immigrate to the United States as a permanent resident.
A K-3 spouse visa allows the foreign spouse of the U.S. citizen to enter the United States on a temporary visa while awaiting processing of the I-130 immediate relative petition. Children of the foreign spouse are allowed to enter on K-4 dependent visas.
Both the I-130 and K-3 spouse visa petitions are always filed at around the same time.
At the current time, only the I-130 immediate relative petition is being processed by the USCIS (since there are no long delays that require issuance of the K-3 spouse visa).