What is a Spider?
A spider is another name for a web crawling bot used by search engines to analyze and rank web pages. The term spider often refers to more complex bots and can be used by web developers to gauge the SEO status of a page or site.
More About Spiders
Spiders, also known as bots or crawlers, systematically explore the internet to index web pages. The results end up in databases that are then used by search engines to suggest content based on a given search query.
The basic function of a spider is to locate web pages, scan them for relevant information and keywords, index that information into the database, and retrieve it when a search query is looking for something similar.
You can help guide spiders on your website by using a robots.txt file, submitting an XML sitemap, or noindexing pages you don’t want to appear in search results. With limited computing power and server resources, sites are not constantly crawled by spiders. Expect spiders to access a site roughly once every three to four weeks.