What is Peer-to-Peer P2P

P2P is the acronym for the words “peer to peer”, which means communication between equals. Computers connect and communicate with each other without using a central server, building, optimizing and managing the bandwidth used so that the best path between all nodes or computers is found.
Due to its characteristics, it’s used to exchange files such as music, videos, documents and complete software packages. Some Internet telephone systems use P2P networks to streamline the transmission of voice and sometimes also stream video (take Skype for instance). Another use of P2P networks is for processing and handling large amounts of information.

Types of P2P networks according to their design

Centralized

It maintains a directory on a central server, to which computers make requests to find the nodes that contain the desired content. Its main shortcoming is that the central server is a weak point: if it crashes, nothing works.

Decentralized and structured

Also known as hybrid P2P. There’s no  directory on a central server, but on several independent computers placed in different locations that make the network easily accesible to other computers.

Decentralized and unstructured

There are no existing computers or nodes that function as central request controllers. All nodes can act both as clients and servers.

Characteristics of decentralized P2P

• Anonymity: users should be able to connect without worrying about their privacy. However, this standard is not always met 100%.
• Scalability: implies more security, by not relying on a central server and its capabilities.
• Independence: the user interface does not require an Internet browser and every computer can run as a client or server.
• Decentralization: handles connections and temporary variables and temporary addresses , and all connected computers are considered equal.

Pros and cons

Advantages

• Cost: many programs are free, which makes them an attractive option for those looking for free content (the legality of this practice is questionable). P2P programs with legal content also exist and, despite having to pay for membership, are a good choice if you want a good price.
• Efficiency: using file sharing is easy and fast.

Disadvantages

• Legality: P2P programes have been questioned for sharing music and videos illegally. This has been a source of controversy.
• Spyware: many programs are riddled with spyware or malware, causing a sluggish performance of your computer, or for it to stop working.
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Via: http://fikobservatory.com/  by creative commons licence.