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In this guide, we’ll teach you the basics of how servers work. This will prepare you for the other guides in this section, which will show you how you can use your server to host services, connect to other computers, and more. A server is a computer connected to the internet that “serves” other computers on the internet. Other computers can send a message to the server. Any computer, including your laptop, can be a server. But usually, servers live in data centers, which are large buildings with many specialized computers connected to the internet. Compared with a laptop, data‑center servers are:
  • Always on, with stable, high‑speed networking
  • Built for reliability and continuous load
Just like they say “happiness is a state of mind”, serving is “state of mind” for a computer. Data center servers are a special kind of computer designed to be really good at serving.
All of the websites, and most of the applications we use today run on servers. A company typically runs many servers with duplicate copies of their software, which lets them serve requests from many users at the same time. Most people don’t use servers as personal computers – not even your average computer programmer next door. Before Zo, only the most hardcore computer users had the motivation and skill to set up and use their own personal server.

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What is a service?

A service is a computer program, also known as a process, that can listen to requests from other computers on the internet. A process on your computer can have a port, which is a mailbox on your computer where the process can “listen” for incoming messages. Many services can run on the same computer, as long as they use different ports. Computers on the internet communicate using specific languages called protocols. When a service runs on your server, it uses a particular protocol to understand and respond to incoming requests.

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Learn more

The numbers used for ports are typically between 1024 and 65535. Numbers below 1024 are reserved for the computer’s official services. These official ports include 80 (for websites), 443 (for secure websites), and 22 (for secure remote access). The rest of the ports are available for other programs to use. While there are common port numbers that many programs follow, these are conventions rather than strict rules.
  • TCP is the foundational protocol that breaks data into small pieces, sends them reliably and in order, then reassembles them on the other side. It ensures messages don’t get lost or mixed up during transmission.
  • HTTP builds on top of TCP and defines the rules for requesting and sending data between computers. It powers most of the services behind the websites and apps you use every day.
  • HTTPS is the secure version of HTTP. It uses encryption (TLS) to keep your data private and verifies you’re connecting to the real server, not an imposter. Often, TLS is handled outside your server by a secure “edge” or “tunnel” that manages encryption and certificates for you.
  • SSH is a secure protocol for remotely accessing and controlling your server. It encrypts all information you send, protecting your login and commands from interception.

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Services on your Zo server

When setting up a service on your Zo server, you only need to provide a handful of settings because we’ve already set up all the hard stuff.
Zo can set up and manage services for you, but it’s helpful to understand what each setting means.
Local portThe port on your server.
TypeThe protocol, either HTTPS or TCP.
EntrypointThe command to start your service.
Working directoryThe folder where the command should run.
Environment variablesAdditional settings for running the command.
After your service is up and running, you’ll get two URLs that you can use to access your service on the public internet. In general, you should:
  • Use the “HTTP Proxy URL” for accessing most web services, like websites and APIs.
  • Use the “Direct Tunnel URL” for non-web services, or if the HTTP Proxy URL doesn’t behave as expected.