Difference between Peer to Peer and Client Server

What is a Peer-to-Peer Network?

Before learning about the difference between peer-to-peer and client-server networks, let us first learn about computer networks in brief.

A computer network is a set of devices (computers) connected to exchange information and resources such as files etc.

The main goals of computer networks are :

• Resource sharing (such as software sharing, program sharing, etc.)
• High Reliability (if one network link fails another can transfer the data).
• Cost Reduction (we can buy only required services from cloud services like GCloud, AWS, Azure, etc.).
• Communication (acts as a communication medium between sender and receiver).
• Load Sharing (a program may run on multiple machines).

There are mainly two types of computer network architecture :

1. peer-to-peer network architecture or P2P network architecture.
2. Client-Server networks architecture.

Now, to learn about the difference between peer-to-peer and client-server networks, we should first discuss the peer-to-peer networks model.

Peer-to-peer has decentralized the simplest form of network architecture where every computer system (node) can communicate with every other computer system (node). In the peer-to-peer network architecture, there is no use of a centralized server as every computer system can communicate with every other computer system directly.

In the peer-to-peer network, each node of the network has equal permission and responsibility for processing the data or information. Each computer network in the peer-to-peer computer network architecture acts as an independent workstation and maintains its security. Every computer system stores data on its disk and can share the data with the rest of the computer systems present in the network. So, we can say that in a peer-to-peer network, each computer system can act as both a server and a client. Hence, each computer network can request service(s) and can also provide the services. The main focus of the peer-to-peer network model is on the connectivity among the computer systems.

Refer to the diagram below to see the basic overview of a peer-to-peer network system architecture.

In a small-scale network (consisting of a lesser number of computer systems), it is easier to manage communication due to direct interconnections between the computer systems. Hence, we can set up a peer-to-peer network architecture at home. The peer-to-peer network architecture is also proffered by SMBs (or small-scale businesses) where there is no need for a centralized server.

Now, that we have gained a good understanding of peer-to-peer network architecture, let us now learn about the client-server architecture so that we can understand the difference between peer-to-peer and client-server networks easily.

What is a Client-Server Network?

A client is a computer system that accesses the services provided by a server. On the other hand, a server is a powerful centralized hub that stores various information and handles the requests of the client(s).

The client-server network model is one of the most widely used networking models. In the client-server network, the files are not stored on the hard drive of each computer system. Instead, the files are centrally stored and backed up on a specialized computer known as a server. Here, a server is designed to efficiently provide data to a remote client. On a large-scale network, there can be more than one server.

Let us discuss the various types of servers:

• File Server :
  A file server is used to transfer files to the client(s).
• Email Server:
  An email server is used to deal with the internal email system.
• Web Server:
  A web server is used to control access to the internet and block any unsuitable websites.
• Print Server:
  A print server is used to deal with all of the printing requests from the client(s).

In a client-server network, there is a specific server and specific clients connected to the server. Refer to the diagram below to see the basic overview of a client-server network system architecture.

The central computer system or the server is used to provide communication and resource sharing between other computer systems present on the network which are known as clients. A client does not share any of its resources, but it requests data or services from a server. The main focus of the client-server network model is on data sharing.

A server is always ON so client machines can access the files and resources without caring whether the server computer system is ON or not. One of the major drawbacks of the client-server model is that if the server is turned OFF (due to any certain reason), the resources present on the server will not be available to the clients.

Examples of Peer-to-Peer (P2P) Model

As discussed earlier, the peer-to-peer network model is suitable for a smaller set of computer systems.

Some of the areas where the peer-to-peer network model is used :

• Napster ($1999$) which is an audio streaming application developed by MelodyVR uses the peer-to-peer network model to upload, download, and exchange music via file-sharing programs.
• Some online gaming platforms also use the peer-to-peer network model.
• Games like StarCraft II, Diablo III, and World of Warcraft are distributed using the peer-to-peer network model.
• The peer-to-peer network architecture is also used in the field of blockchain.

Examples of Client-Server Architecture

The client-server network model is suitable for a larger set of computer systems. The significant increase in the scale of devices can be easily handled in the case of the client-server model as there is no need for direct linkage among the computer systems. If any new device comes into the network then it can directly contact the centralized server after being authenticated.

Some of the areas where the client-server network model is used:

• One of the most famous examples of the client-server model is our web browsers. The web browsers act as a client because it requests information about a certain thing from the web servers. So, a web server serves and handles the requests of users made through web browsers.
• Similar to the web servers, the database servers also respond to the queries (requests) of the client. If the client is properly authenticated then the database server returns the result of the query as a response to the client.
• Other examples of the client-server model can be Internet mail Systems which use mail servers to communicate with other mailing systems.

Advantages and Disadvantages of the Peer-to-Peer Model

Let us now discuss some of the advantages and disadvantages of the peer-to-peer model.

Advantages:

• The resources like files are easy to share as the computer system is directly connected.
• The peer-to-peer network architecture is less expensive to implement because it eliminates the extra cost required in setting up the server.
• It is very reliable, if one computer system of the network fails then it will not affect any other part of the network. It simply means that the files located on the failed system are not available to the other users at the time.
• The peer-to-peer network architecture is easy to set up and maintain as each computer manages itself.
• In the P2P network model, the response time is low as the computer systems are directly connected.
• We can easily share devices like printers among all the connected systems of the network.

Disadvantages:

• The peer-to-peer network architecture is not very secure, the data and other shared resources can be easily discovered and used by unauthorized users.
• Since each computer system acts as an independent server and client, the respective computer system user must be trained to perform an administrative task.
• As there is no centralized server in the network, there cannot be a central backup of files and folders.
• Each computer system has its anti-virus scanner and backup schedule so there is an extra cost for this software (for each computer system).
• The peer-to-peer network model is mainly suitable for small-scale businesses and houses.
• The P2P network model becomes less stable if the number of the peer (computer system) increases. As the wired connections between the computer systems increase, the management becomes difficult and hence, the network becomes less stable.

Advantages and Disadvantages of the Client-Server Model

Let us now discuss some of the advantages and disadvantages of the client-server model.

Advantages:

• All the files are allocated on the server, so, backing up data is a lot easier than backing up each computer system separately. This is known as a centralized backup.
• Anti-virus software is managed centrally. All computer systems are protected as files are managed in one place.
• Problems on the network can be tracked and diagnosed and often fixed from one location. Hence, maintenance is easy.
• The security is increased as each user (representing a computer system) needs to be authenticated to access the resources from the central server.
• There are different levels of access, so, we can control the data to be shared with specific users.
• Users can access the data remotely.
• The client-server network architecture is more robust and can be easily extended.
• The client-server network model is suitable for both small-scale businesses and large networks.

Disadvantages:

• There is an additional expense for the central server.
• If the server itself is down, there is no access to the files and data stored on the server.
• Special staff such as a network manager is needed to maintain the central server. Hence, its maintenance is costly are requires manpower as well.
• In a situation when there are numerous client requests made simultaneously, the server becomes busy resulting in traffic congestion on the network.

Difference between Peer-to-Peer and Client-Server

As we have discussed the peer-to-peer network model and client-server network mode, let us now discuss the difference between the peer-to-peer and client-server network models.