Purgatory/

I remember one time to ask to my parish priest what does a purgatory mean in a simple and biblical way, I am sure he did his best to explain to me in a way he thinks I can understand it. The main reason I asked was , I did not have much knowledge apart from  what  my mum, my mum is the sole and basic  teacher of me in religious and many other great ideas,  told me about it, so I want to know, shall I say it intellectual way. I know to believe this kind of mysterious  concept should not be based on some human intellect.Saying that it would not be a bad idea to look for explanation that helps to make your believe as concert as possible. I find this link helpful to understand what purgatory exactly mean.