Answer:

Server

A computer on a network that shares resources for others to use is called a server. A server is a device or computer program that provides services to other computers or clients on the network. It acts as a central hub that manages network resources and enables communication between clients.

Types of Servers:
- File Server: A file server is a computer that stores files and allows other computers on the network to access and retrieve those files. It provides shared storage space for documents, images, videos, and other files.
- Print Server: A print server manages printers on the network and allows users to send print jobs from their computers to the printer. It controls the printing process and ensures efficient utilization of printer resources.
- Web Server: A web server hosts websites and web applications. It delivers web content to clients who request it through a web browser. Web servers handle requests for web pages, process server-side scripts, and transmit the requested data back to the client.
- Database Server: A database server stores and manages databases. It provides access to the database for clients and handles queries and transactions. Database servers ensure data integrity and security.
- Mail Server: A mail server manages email communication within a network. It handles the sending, receiving, and storage of emails. Mail servers use protocols such as SMTP (Simple Mail Transfer Protocol) and POP3 (Post Office Protocol) to facilitate email exchange.

Server Characteristics:
- Reliability: Servers are designed to be highly reliable and available. They often have redundant components, such as power supplies and hard drives, to prevent downtime.
- Scalability: Servers can handle a large number of client requests and can be scaled up or down depending on the network's needs.
- Security: Servers have built-in security measures to protect against unauthorized access and data breaches.
- Performance: Servers are optimized for performance and can handle resource-intensive tasks efficiently.

In conclusion, a computer on a network that shares resources for others to use is called a server. Servers play a crucial role in managing and providing various services on a network, such as file sharing, printing, web hosting, database management, and email communication.