Recently I've read the following about configuring ec2 instance:
"First up, transfer your private key (*.PEM) file over to the Linux server using and SCP tool. In my case, I always use WinSCP to achieve this. It’s a simple tool and pretty straightforward to use. Once the key is transferred, run the following command to change the key’s permissions:
#chmod 400 <Private_Key>.pem "
Is it really necessary to keep PEM file on the instance? How it can be useful? Because I can connect to the instance without transferring it.