There are numerical limits on the number of immigrant visas that can be granted to aliens form any one foreign country. The limit is based on place of birth, not citizenship. Because of the numerical limits, this means there is a waiting time before the immigrant visa can be granted. The terms current/noncurrent refer to the priority date of a petition in preference immigrant visa cases in relationship to the immigrant cut-off date. If your priority date is before/earlier than the cut-off date according to the monthly Visa Bulletin, your case is current. This means your immigrant visa case can now be processed. However, if your priority date is later/comes after the cut-off date, you will need to wait longer, until your priority date is reached (becomes current).