For dedicated servers, the most commonly offered operating systems (OS) are:

1. Linux Distributions

• CentOS: A popular open-source distribution, ideal for servers and web hosting.
• Ubuntu: Known for its ease of use and large support community, widely used in hosting and development environments.
• Debian: A stable and secure choice, often used for web servers and applications.
• Fedora: A cutting-edge, community-driven distribution, frequently used by developers and for testing newer technologies.
• Red Hat Enterprise Linux (RHEL): A commercial, enterprise-grade OS for businesses requiring extensive support.
• Arch Linux: A rolling-release distribution for those who need the latest software, often chosen by advanced users.

2. Windows Server Versions

• Windows Server 2022: The latest version, offering robust features for enterprises, security improvements, and performance upgrades.
• Windows Server 2019: A stable choice, often used in environments where compatibility with older Windows apps and services is required.
• Windows Server 2016: Still widely used, offering a balance between legacy app support and modern features.
• Windows Server 2012 R2: Ideal for clients who need a familiar interface and legacy support.

3. Other Specialized OS

• FreeBSD: A Unix-like OS known for its performance and security, preferred by advanced users and those running certain network services.
• CloudLinux: Often used for shared hosting environments due to its enhanced security and performance.
• OpenSUSE: A versatile Linux distribution that’s suitable for both development and production environments.

Additional Options:

• Control Panels: You can also choose server management tools like cPanel/WHM, Plesk, or Webmin, which are often offered alongside Linux distributions to make server management easier.
• Virtualization OS: For setting up virtual environments, options like VMware ESXi or Proxmox are also available.

The exact OS options depend on the hosting provider, but these are among the most common choices for dedicated server setups.