Server
also: servers
A computer that stays switched on and waits for other devices to ask it for something, like a web page or saved information, then sends it back.
Either a machine or a program that listens for requests from clients and responds to them. A web server might return pages, run backend code, or read from a database. Servers usually run in data centers or on cloud platforms.
A server is like the person behind a deli counter. They wait for customers, take orders, prepare what's asked for, and hand it over. They're there whether or not anyone is in line.
When your agent says "start the server" or "the server crashed", it means the behind-the-scenes part of your app is running, or isn't. That explains how a page can load but still fail to save anything.
The server isn't running, so the page can't load any data. Run npm run dev in the terminal and refresh.
The site loads but saving a booking fails. Check the server's output for errors before changing the page itself.
Thinking a server has to be a special, huge machine. Any computer running the right program can act as one, including your own laptop while you develop.