Explain network edge

• It defines those computers of the network used at the edge of the network. These computers are known as hosts or end systems. 
• Hosts can be classified into the following two types:

Clients:  refer to the computer systems that request servers for the completion of a task. The clients are generally called desktop PCs or workstations.

Servers: Refer to the computer systems that receive requests from the clients and process them. After processing is complete, the servers send a reply to the clients who sent the request.

• The concept of clients and servers is essential in the network design. The various networks design models are as follows:

Peer to Peer network

• In this network group of computers is connected together so that users can share resources and information. 
• There is no central location (server) for authenticating users, storing files or accessing resources and each of them works as both client and server. 
• This means that users must remember which computers in the workgroup have the shared resources or information that they want to access.

Advantage:

• It is easy to set up. 
• There is no need of any committed server as each peer acts as both server and client. 
• The network implementation is quite cheap. 
• The resources of a peer can be shared with other peers very easily in the network.

Disadvantage:

• The speed of the network decreases due to heavy usage. 
• It is not easy to keep track of information on each computer. 
• There is no central backup of files and folders. 
• Network and data security are weak.

Client/Server network

• A client/server network is a system where one or more computers called clients connect to a central computer named as server to share or use resources.
• The client requests a service from server, which may include running an application, querying database, printing a document, performing a backup or recovery procedure. The request made by the client is handled by server.
• A client/server network is that in which the files and resources are centralized. This means that the server can hold them and other computers(Client) can access them.

Advantage:

• The server system holds the shared files.
• The server system can be scheduled to take the file backups automatically.
• Network access is provided only to authorize users through user security at the server.
• The server system is a kind of central repository for sharing the printer with clients.
• Internet access, e-mail routing and such other networking tasks are quite easily managed by the server.
• The software applications shared by the server are accessible to the clients.

Disadvantage:

• The implementation of the network is quite expensive.
• An NOS (Network Operating System) is essential.
• If server fails, the entire network crashes.
• There may be congestion if more than one client requests for a service at the same time.