Sockets, Async vs Synch - Freezing Problem

Question

Hi, I built a FTP client just for pratice in C#. I'm using synchronous sockets in blocking mode in a while loop in windows forms. So, everytime I'm doing a file transfer the program freezes till it's completely done. Functinoality of the sw is achieved but has this freezing effect persists during transfers. Is this due to the fact the receive/send method in while loop? Could this be avoided using asynchronous sockets? Simply, is that normal for a program to freeze while running in a while loop continuously receiving bytes? But it works. Thank you. JJ