ServerlocalhostDatabasemyDBUserrootPasswordpass

localhost, often referred to as the loopback address, is a standard hostname that refers to the local computer. It is used by software to establish network connections to services running on the same machine. The most common IPv4 address associated with localhost is 127.0.0.1, and the corresponding IPv6 address is ::1. These addresses route traffic back to the originating device, bypassing any physical network interface.

Practically, localhost is implemented via a loopback network interface. On Unix-like systems this interface is usually named lo, while Windows maintains a loopback adapter. The mapping between the hostname localhost and its IP addresses is typically defined in the system’s hosts file (for example, 127.0.0.1 localhost and ::1 localhost). Applications rely on this name resolution to refer to the local host without needing a real network route.

Usage and implications: developers frequently bind services to localhost (for example, 127.0.0.1) to ensure that a server is only accessible from the same machine, which can aid testing and security during development. To expose a service to other machines, the service must bind to an external address such as 0.0.0.0 or a specific network interface IP.

In containerized or virtualized environments, localhost refers to the container or VM itself rather than the host system, affecting how services connect across boundaries. Understanding localhost helps in secure development practices and correct network configuration.