What is a Server?

When you hear the word "server" in the context of computers, this can be referring to both hardware and software. While server hardware is targeted towards reliability and uptime, any computer can run the software needed to host a server.

Hardware

When most people think of a server, they imagine one in a data center at a large tech company. These servers have enterprise-grade hardware that are built to attain as close as possible to 100% uptime. This includes features like error-checking RAM, hot-swappable hard drives and redundant power supplies. Servers often incorporate RAID – or a Redundant Array of Independent Disks – that allow hard drives to mirror themselves in real-time in the event that one fails.

These form factors are traditionally known as "blade" or "rack" servers. Data center servers use this compact design because it allows them to be stored efficiently with each unit having it's own cooling. Tower servers are also a common form factor for a home or small business server. These have the features of a rack server, but in a discrete form factor that work excellent when you don't need multiple servers.

Servers often operate "headless" which means they do not have a monitor, mouse or keyboard and are instead controlled as needed through a remote connection like SSH or RDP.

Desktop computers that are created towards consumers are targeted at price points and features hardware that is geared towards a client environment with a monitor, mouse, keyboard and desktop environment.

While they can maintain excellent uptime, hardware malfunctions and errors can result in downtime because they do not have redundant hard drives, power supplies or RAM. Without a backup solution in place, this can result in permanent data loss if a hard drive fails or a power surge occurs.

Consumer-grade computers can be used as a server when the appropriate software is installed and precautions are taken to offset the hardware differences, such as a consistent and secure onsite and remote backup solution. Periodic hardware tests, such as running a Power On Self Test or maintenance tests (like ram and processor tests), can got a long way to ensuring your server doesn't go offline unexpectedly. SMART allows you to monitor your hard drives for any potential signs of failure.

they have a processor, memory, storage, graphics cards, and a network card.

Software

In addition to hardware, a server also related to software. This is in relation to the server-and-client model of networking where servers are dedicated to handling the requests of clients. Linux distributions, such as Debian, powers an estimated 95% of the top one million web servers and all super computers. This is because it is incredibly modular and permissively licensed making it easy to customize or extend.

Through your operating system, such as the same Linux distributions used to power most servers, a computer can accept incoming connections over your network. Using ports, similar to an old phone switchboard, we can connect services running on our server to the outside internet using our local network router.