A server is a computer system or software program that provides resources or services to other computers or programs, commonly known as clients, over a network. Servers can be used to manage and store data, host applications or websites, facilitate communication and collaboration, and perform other tasks required by clients. Servers can range from small-scale single-purpose systems to large-scale multi-purpose data centers, and can run on various operating systems and hardware configurations. Servers are typically designed to be highly reliable, secure, and scalable to meet the needs of their users.