What is Web Crawler?

A Web crawler or Spider is a bot, downloads & indexes content from all over the internet. The goal of such a bot is to learn about the webpage’s content so that the information can be retrieved when it’s needed. They are called “web crawlers” because crawling is the technical term for automatically accessing a website & obtaining data via a software program. These bots are almost always operated by search engines. By applying the search algorithm to data collected by web crawlers, search engines can provide the solution of the user’s query. Search Engines like Google, Bing, etc. use web crawlers to access data.

What is Search Indexing?

Search indexing is like creating a library card catalog for the internet so that the search engine knows where on the internet to retrieve the information when a user searches. It can also be compared to the index in the back of a book, which lists all the certain topics & phrases are mentioned in the book.

How They Got Details?

In the context of search indexing, metadata is the data that tells about the webpage to the search engines. Often the meta title & description are what will appear on search engines result page, as opposed to content from the webpage that’s visible to users. So if you want to rank on the search engines then make meta title & description BEST !!

How They Work/Crawl?

The internet is constantly changing & expanding, so it’s not possible to know the total number of web pages. Web crawlers start from a seed or list of known URLs. As they crawl those webpages they’ll find hyperlinks to other URL’s & they add those to the list of pages to crawl next.

How They Affect SEO?

SEO stands for Search Engine Optimization & it is the discipline of readying content for search indexing so that a website shows up higher in search engine results. If they don’t crawl a website then it’s not indexed & won’t show up in search results. For this reason, if the owner of the website wants organic traffic so it’s necessary not to block web crawlers.

Some Crawlers!

There are so many web crawlers active on the internet :

• Google: Googlebot (actually two crawlers [Googlebot desktop & Googlebot Mobile] for desktop & mobile searches)
• Bing: Bingbot
• Yandex (Russian): Yandex bot

There are also many other search engines active on the internet.