A client is the one asking for something — a customer of a firm, or in computing, the program or device requesting data — while a server is the one providing it, whether that is a computer serving a website or a person serving food. Think of a browser as a client asking a website's server for a page: the client requests, the server responds.
The core difference
A client requests or receives a service; a server provides it.
- client — a person, organisation or program that requests services or data, such as from a professional firm or from a server: download the desktop client to sync your files offline.
- server — a computer, program or person that provides data or services to others: the website went down when the server crashed.
How to tell them apart
Outside computing, the pattern still holds: a client is the one being served, such as someone paying a solicitor or accountant for advice, while a server is the one doing the serving, such as a waiter recommending the fish special. In computing, the relationship is the same shape — a client, whether that is a web browser, an email program or a game client, sends a request, and a server, a computer or program elsewhere on the network, answers it with data or a service.
Server has a couple of other everyday senses worth knowing. It can mean a restaurant worker who waits on tables, or an online community platform, especially on Discord, that only its members can access.
