I cannot move my file in Linux operating system

Hy guys, I use M.V commend for move my file in Linux operating system. For example I want to move my bodyguard file form A folder to B folder. But my Linux can not move it. I use M.V ( in linux commend line ) bodyguard ( file name ) B ( B= where my file is being moved ) commend. I am so confused about it. Why I face this problem? How can I solve this? Please help me.
