If you have root-level access to a hosting server, it indicates that you'll have full control of it. In other words, you'll be able install any server-side application regardless of the changes that it'll make to the software setting on the server, and you're able to both access and change any kind of file, including system files, and change any settings. This can be done by connecting to the server as a root user which has full privileges to do all these things and to create other users, which includes users who also have full privileges. This connection can be established through a web-based graphical interface or a Secure Shell console. For safety reasons, it's recommended that you make a different user for your daily work and use the root user only when you have to customize the server or to install software which may be required by a script-driven application that you want to run.
Full Root-level Access in VPS Servers
You'll be able to take care of your new VPS servers at the root level regardless of the plan that you've picked, as long as the server is ordered with either the cPanel or the DirectAdmin hosting Control Panel, or without Control Panel at all. In the first case, a large number of system settings can be managed via an easy to navigate web-based interface, whereas in the second, you will need to do everything using a console, until you decide to set up a Control Panel yourself. Either way, you will have full control over the VPS plus any system or custom content on it at all times, which makes this type of web hosting perfect for any app that you cannot run with a shared web hosting account due to the restricted level of access - frameworks, VoIP and audio/video streaming software, and many others. The last VPS Control Panel option is Hepsia, but the root access to your server will be restricted.
Full Root-level Access in Dedicated Servers
You'll have full root-level access to your dedicated server no matter which plan you choose throughout the registration process, as long as the server is ordered with cPanel or DirectAdmin, or with no website hosting Control Panel at all. In all of these 3 cases, you're able to modify any part of the software environment in any way you see fit, that makes our server packages suitable for resource-demanding apps with specific requirements which cannot be covered when you use a shared hosting account. The difference between these options is that when you choose cPanel or DirectAdmin, you'll have a web-based graphical interface to take care of numerous server-side options and any site content that you generate or upload, whereas if you order the server devoid of Control Panel, you'll have to do everything with a Secure Shell console or to install a Control Panel of your liking, if it is compatible with the OS that you've chosen during the registration process. With the third Control Panel option that you'll be able to pick on the order page - Hepsia, the root access will be limited.