A host is a computer or device that interacts with other hosts within a network. Also referred to as network hosts, these encompass both clients and servers that transmit or receive data, services, and applications.
Unlike intermediary network devices such as switches and routers, which are categorized as nodes, a host is defined by its requirement for an IP address. Essentially, while all hosts are nodes, the reverse is not true. Nodes refer to anything connected on a network, but hosts need an Internet Protocol (IP) address to operate.
Hosts communicate using various protocols, including Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). In a TCP/IP network, each host has a unique IP address, derived from its host number and network identity. Communication between hosts is governed by protocols found in the transport layer of the Open Systems Interconnection (OSI) model.
The term host has various meanings within IT, shaped by context. It could denote a device or program offering services to smaller or less capable devices. Below are the key contexts in which the term host is used.
A web host is a server that stores and transmits data for one or more websites. It can also refer to the service provider that leases this infrastructure.
A cloud host utilizes cloud computing technologies, allowing multiple servers to operate as a single system, ensuring website performance. This setup often involves a network of servers deployed across various data centers.
The term virtual host can refer to the technology enabling multiple domains or applications to utilize a single physical server or companies offering virtual infrastructure services.
Users can access remote hosts located elsewhere, using either a private network or the internet. This approach provides remote access to servers or host computers for services like remote desktops.
This refers to hardware that provides the necessary resources to support virtual machines, part of the server virtualization process.
In mainframe contexts, the mainframe can act as a host offering services to connected workstations.
A hostname is a human-readable name identifying a host within a domain. Within a local area network, a server may have a nickname, such as mailserver1. On the internet, a hostname constitutes a part of a web address, made up of a subdomain, domain name, and top-level domain.
