What does the fullness of the Gentiles mean?

In Romans 11:25, Paul discusses a 'fullness of the Gentiles' which signifies a specific number of Gentiles who will come to faith in Christ. This number is fixed in God's eternal plan, emphasizing that salvation is not about quantity but divine selection. Once this fullness is reached, the partial blindness of Israel will be lifted, allowing all elect Israelites to be saved. This interconnection between the salvation of Gentiles and Israel illustrates God’s sovereign orchestration of redemptive history.