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Client

PropertyValue
descriptionSoftware or device that requests data or services from another system, usually a server.
tagsref

A client is software or a device that requests data or services from another system, usually a server.

In web contexts, a client is often a browser, but the term is broader than that and can also refer to desktop apps, mobile apps, API consumers, or command-line tools.

What it does​

A client initiates communication with another system.

It is commonly used to:

  • Request pages, data, or services from a server
  • Render or display responses to a user
  • Send user actions or data to a backend
  • Consume an API
  • Interact with remote systems over HTTP or other protocols

Core concepts​

Requesting side of a client-server model​

In a client-server architecture, the client initiates requests and the server responds.

That is the main reason the term appears so often in networking and web development.

Not only browsers​

A client is not limited to a web browser.

Mobile apps, desktop apps, bots, scripts, and terminal tools can all act as clients.

User-facing or programmatic​

Some clients are directly used by people, while others operate programmatically.

For example, a browser is a user-facing client, while a script calling an API is a programmatic client.

Common use cases​

  • Browsing websites
  • Mobile apps calling APIs
  • Desktop apps syncing with remote services
  • Command-line tools sending requests
  • Frontend apps talking to a backend

Practical notes​

  • Client is a role in an interaction, not a statement about whether software is local or remote.
  • A system can act as a client in one interaction and as a server in another.
  • In web development, the client side is usually associated with the frontend.
  • Calling the client "usually your browser" is too narrow for technical documentation.

Sources Used​

Frequently Asked Questions​

Is a client always a browser?​

No. A browser is one common client, but many other apps and tools can act as clients too.

Is client the opposite of server?​

In many architectures, yes. The client requests and the server responds.

Can a CLI tool be a client?​

Yes. Many command-line tools act as clients when they call an API or remote service.