Mostly if there is a vacancy or a job opening the organization will create a platform for interested candidate to applied which include submission of CV. Within that period the organization goes through the profiles and CV of most of these candidates thereafter selecting the best out of them.

So if you apply for a job and you were not call within 3weeks that means you were not selected and if eventually you were later called after 1month that means there is another vacancy.

My opinion what's yours