Pull vs Push Technology

John Spacey, updated on March 06, 2017

Pull technology refers to clients that make requests to servers. This is the traditional way to structure a client/server architecture.

Push technology refers to servers that initiate information updates to clients.

The Difference

The difference between push and pull technology comes down to who initiates information updates. If the client initiates requests, it's pull. If the server initiates updates, it's push.

Example

Traditionally, clients pull information from servers. For example, a web browser requests web pages from web servers. Many web browsers now support push notifications whereby a user can request notifications from a site they trust such as a news source. In this case, the web server will push information to the web browser when it becomes available.

Polling

Polling is when a client continually asks a server if updates are available. Although this is technically a pull, it is considered a way to implement push technology. This is done because security features of networks or platforms may prevent certain types of inbound connections to clients.

Pull Technology vs Push Technology
	Pull Technology	Push Technology
Definition	A client that requests information from a server.	A server that initiates information updates to a client.
Example	A web browser requests a web page.	An email server transmits an email to an email client.