The term "Google spider" is commonly used to refer to Google's web crawlers, which are automated programs or bots that systematically browse the internet, following links from one webpage to another. These web crawlers are also known as "Googlebot."

Googlebot plays a crucial role in the process of indexing web pages for the Google search engine. When you perform a search on Google, the search results are not generated in real-time by searching the entire internet again. Instead, Google has already crawled and indexed billions of web pages in its vast database.

Here's how the process typically works:

1. Crawling: Googlebot starts by visiting a few web pages and follows the links on those pages to discover new URLs. This process is known as crawling. It continues this process, jumping from one page to another, until it has visited and processed a significant portion of the web.

2. Indexing: As Googlebot crawls web pages, it analyzes and indexes the content it finds on those pages. Indexing involves understanding the content and context of a page, identifying keywords, and storing this information in Google's index, a massive database of web pages and their content.

3. Search: When you enter a query in the Google search bar, Google's search algorithms use the indexed data to quickly retrieve relevant results from its database. The results are then ranked based on various factors, such as relevancy, authority, and user experience.

It's important to note that while Googlebot aims to crawl as much of the web as possible, it may not crawl every single page on the internet due to factors like website restrictions (e.g., through a robots.txt file) or technical issues.

By regularly crawling and updating its index, Google can provide users with up-to-date and relevant search results when they search for information online. This process enables Google to offer a vast and diverse range of web pages to users in a matter of milliseconds.