A dedicated server is a single physical computer engineered to support multiple users, run a large number of different services and applications, and manage, store, send and process data 24-hours a day. A dedicated server allows for all the resources of the physical computer to be "dedicated" to one client and the hardware resources are not shared with any other clients. This is in contrast to shared servers and cloud servers where the resources of the physical computer system are shared amongst many clients.
The server must be able to handle a lot of visitors when your website experiences increased traffic. Online shops, for instance, tend to place high demands on the stability of server capacities. Many shop owners in the eCommerce segment prefer to know that their customer data is hosted on a server that is not shared with others. A dedicated server with “genuine” root access is the better choice in these cases. Moreover, a dedicated server offers more web server options.
The answer to this question largely depends on two factors. Are you new to server technology and not very interested? In this case, Windows is the easiest option to get where you want to go. Do you already have experience with Linux or would you like to familiarize yourself with this operating system? If so, Linux gives you more freedoms to configure your server, and you will be using an operating system that is less vulnerable to attacks from the Internet. Linux is also open source and therefore free.