Google requires large computational resources in order to provide their services. This article describes the technological infrastructure behind Google's websites, as presented in the company's public announcements.

The original hardware (circa 1998) that was used by Google when it was located at Stanford University included:

Servers are commodity-class x86 PCs running customized versions of Linux. The goal is to purchase CPU generations that offer the best performance per dollar, not absolute performance. How this is measured is unclear but is likely to incorporate running costs of the entire server and CPU power consumption could be significant factor. Servers as of 2009 consisted of a custom made open top systems containing two processors (each with an unknown number of cores or interconnected processing units) a considerable amount of RAM spread over 8 DIMM slots housing double height DIMMS and two SATA hard drives connected through a non-standard ATX sized power supply. According to First April publication by CNET, Each server has a novel 12 volt battery to reduce costs and improve power efficiency

Web server can refer to either the hardware (the computer) or the software (the computer application) that helps to deliver Web content that can be accessed through the Internet.

The most common use of web servers is to host websites, but there are other uses such as gaming, data storage or running enterprise applications.

The primary function of a web server is to deliver web pages on the request to clients using the Hypertext Transfer Protocol (HTTP). This means delivery of HTML documents and any additional content that may be included by a document, such as images, style sheets and scripts.

A user agent, commonly a web browser or web crawler, initiates communication by making a request for a specific resource using HTTP and the server responds with the content of that resource or an error message if unable to do so. The resource is typically a real file on the server's secondary memory, but this is not necessarily the case and depends on how the web server is implemented.

While the primary function is to serve content, a full implementation of HTTP also includes ways of receiving content from clients. This feature is used for submitting web forms, including uploading of files.