List of Proxmox important configuration files directory

Ok, this is it, there are many times when i need to find the path to certain configuration regardless of Proxmox or LXC or KVM or OpenVZ configuration file and i always need to 'remember' where it is and if you do this daily in and out, you might have an idea, if not, this is just another digging the web task! How about recording all these down for me instead? Hence, here are all the important path for anyone who needs it when dealing with Proxmox!