A rack server is a type of computer server that is designed to be mounted in a rack enclosure. A rack is a frame or enclosure that holds multiple servers and other electronic equipment in a vertical orientation.
The servers are typically mounted in the rack using slide-in rail systems, which allow for easy installation and removal of the servers.

Rack servers are commonly used in data centers and other environments where multiple servers are needed to support a large number of users or applications.
They are also used in cloud computing environments, where they are used to provide scalable and flexible computing resources. The servers can be in different form factors such as 1U, 2U, 4U, 6U etc depending on the size and capacity of the server.

Rack servers typically have a higher density of processing power and storage capacity compared to traditional tower servers. They also allow for better airflow and cooling,
which helps to keep the servers running at optimal temperatures and reduces the risk of overheating.

Rack servers are usually managed remotely via a web-based interface or other management software,
which allows IT administrators to monitor and control the servers from a central location.