Search engines implement a crawling and indexing process that allows us to find virtually any information we are looking for on the internet. With those processes, they are able to analyze pages and identify which are relevant to a specific user query.

But how exactly do they do this?

They have a built-in computer program that automatically searches documents on the internet. Commonly known as crawlers, spiders, or bots. They are in charge of navigating through sites looking for information and categorizing it. Spiders are programmed for repetitive actions so that browsing is automated.

How do Spiders work?

In order to gather all the information search engines need to render relevant results, spiders take three steps:

First, they scan throughout the internet looking for information. Then, they assign the information they find to certain categories depending on the content and its context. Third, they index and catalog those pages that are relevant, so the information is available for users.

Besides being responsible for indexing websites, spiders can also be used for other purposes. These include:

  –  Assist in price comparison for products on the internet. They search for information about products so that prices or data can be compared accurately.

  –  Work in the area of data mining. They collect emails or companies’ addresses that are available to the public.

  –  Collection of data for page views, or incoming or outbound links.

There are a few ways for you to block spiders from accessing your site. Implementing what it’s called a crawler directive, you’ll be instructing them not to browse or index specific pages within your website. The most popular instructions are meta tags and robots.txt. For example, if you don’t want one of your pages to be indexed by search engines, then adding the noindex tag should do the trick.