Forum Moderators: phranque
You might want to check out [en.wikipedia.org ]
How will this limit me?
That depends on how much server control has been implemented in the hosting company's control panel.
You may not need it. For most php/MySQL basic hosting, it's not really necessary.
If you need to run custom software on your server, or need "low level" access to the machine for any other reason, it's critical.
TJ