Hosts File

Hosts file is a local name lookup file. On Unix-like systems it usually lives at /etc/hosts; on Windows it lives under System32\\drivers\\etc.

Entries are simple: an IP address followed by one or more hostnames. The operating system checks the file before asking DNS, so it is useful for local development, testing migrations, blocking known names, or pointing a hostname at a temporary server.

That power cuts both ways. A stale hosts entry can make a site look broken long after DNS is correct. Keep comments clear, group related entries, and remove temporary overrides when the job is done.