Everyone probably knows that servers are the basis of the internet. Millions of websites such as ICE Casino are hosted on servers, and when you visit one of these sites, you are actually connected to the server where the files of that site are located. However, this is not the only way the internet works, and it is possible for computers to communicate with each other without using servers at all. This is simply called peer-to-peer technology, and this article will explain how it works and where it’s used.
What Is the Meaning of Peer-to-Peer?
In the early days of the internet, users needed an “intermediary” to communicate with each other. These intermediaries were servers, and without them, you could hardly use the internet. For example, suppose user A wants to access a file belonging to user B:
- User B would upload this file to a server.
- User A would connect to that server and download the file.
In other words, users could not communicate directly. This can be explained as follows:
- User A (peer) — Server — User B (peer)
But in the late ‘90s, a new network protocol was developed. In this protocol, the network was built on a distributed application architecture. To put it simply, it was possible for users to connect directly to each other’s computers and create a network among themselves without using servers at all. It looks as follows:
- User A (peer) — User B (peer) — User C (peer)
Here you see an example of a network created between three users without the need for a server. The number of users in such a network can be thousands or even tens of thousands. This new network model was called “peer-to-peer” (P2P). The traditional server-based system explained above has started to be called the “client-server model.”
The first popular application for P2P networks was Napster. Napster was a music-sharing application that emerged in 1999 and was based on the P2P network. Basically, its users could share music with all other Napster users. Because there was no central server controlling such a network, it was theoretically impossible for Napster to be censored or shut down. Napster was the first practical application to show what P2P networks can do.
It Is Not Limited to Sharing Music
Music wasn’t the only thing that could be shared on P2P networks. If you put together hundreds or even thousands of computers, you get serious computing power. To use and direct this power efficiently, a “central authority” is required to assign various tasks to the computers connected to the P2P network, but by definition, P2P networks cannot have central servers. Instead, users can be selected to temporarily replace such a server. For example, a user who is connected to a P2P network but is not actively using the network at that time can take on the role of “administrator” to use the network more efficiently for a certain period of time. In P2P networks, such computers are called “nodes.”
P2P networks with nodes work much faster and more efficiently. Back to the Napster example: When you search for a particular song, the computer assigned as the node determines which user with that song is geographically closest to you, thus speeding up the download. In this respect, P2P networks using nodes can be considered an “internet” in themselves. This internet is only for the users of that network, and the network optimization is performed by the users. It is also possible to define P2P networks as structured (DHT) or unstructured depending on the node type, but that would be too much information: For now, it is enough to know that these networks can generate serious computing power. This power can be used for different purposes with computers designated as nodes: You can do more than share music.
For example, you can create a cryptocurrency by making a blockchain run on a P2P network. Bitcoin and hundreds of other coins are built on this principle. Some users in a P2P network are miners, some are nodes, and they use the jointly generated computing power to find new blocks and confirm transactions. This is what is meant by the “decentralization” of cryptocurrencies: They are not controlled by a central authority (for example, a server), and transactions made on the network are also controlled by the network.
This is just the beginning: With a P2P network, you can offer a distributed file storage service. Files uploaded to the network for storage are shared among all users, thus obtaining theoretically unlimited storage space. You can also use such a network for content delivery, for example, by creating a communication protocol called “torrent.” BitTorrent (and all other torrent apps) essentially connects you to a P2P network and assigns a different status to each user based on how much they share. You can also create an encrypted communication application with this technology: Even the world’s largest armies use P2P networks as a war strategy. In short, the only limit to the uses of a network protocol that connects users directly without the need for an intermediary is your imagination.