Developer Dictionary
Localhost
Definition
A hostname that means "this computer".
Deep Dive
Localhost is a hostname that specifically refers to the current computer or device being used. In network terminology, it acts as a loopback interface, meaning that any data sent to localhost is immediately returned to the same machine, bypassing the network interface card (NIC) and external network infrastructure. This internal routing mechanism is crucial for development and testing, allowing applications to communicate with themselves without external network dependencies.
Examples & Use Cases
- 1Developing a new website on a developer's machine, accessing it via `http://localhost:3000`
- 2Running a local database server on a laptop and connecting to it from an application also running on the same laptop
- 3Testing an API endpoint configured to listen for requests on the local machine's loopback address.
Related Terms
127.0.0.1Loopback AddressDevelopment Environment