Search engines crawl and index everything that is found on the internet—everything that is displayable on the surface web. While some people think that these two things are the same, they really aren’t.
Crawling vs. indexing: what is the difference?
That is what we will learn today.
In a nutshell, crawling is a search engine activity where it just passes through the World Wide Web for content. Indexing, on the other hand, is a process where the search engine appropriately labels web material. This way, its database is organized.
Now, let us take a closer look.
What is Crawling and Indexing?
To help us better understand what crawling or indexing means, we need to use an analogy. Also, let us just focus on Google.
Think of Google as a person that you are leading on a tour. If you allow Google to take a look inside a museum, particularly inside a room, he can see everything that is in it. This is the equivalent of crawling.
As Google takes a peak at what is in the room, he might see a sign saying that he can call other people to see the room. What this means is that he can list down this room and index it. In time, Google might get asked for something by someone, like a vase.
Since Google knows there is a vase inside that museum, he will lead the person there. On the other hand, that same room may say that Google is not allowed to tell people what he saw. A room like this is called NOINDEX.
In this case, Google was still able to crawl that page but did not list it down, and Google will not show the room to anybody, even if Google knows what is inside that room.
Another thing that can happen is that Google is not even allowed to enter that room. What this means is that Google cannot “crawl” it. Google cannot even see what is inside that room because it is not allowed to do it.
If this happens, Google does not know what to do with it. The contents of the room are locked inside. In this case, Google did not crawl the room, much less index what is inside. But even so, Google can still index the outside of the room, but not the contents.
If the room was labeled Egyptian Artifacts, then Google can still tell people that it knows of a room that is labeled as Egyptian Artifacts. However, Google cannot tell people what is inside, so it is up to the people to do something to open that room and see the content.
The room is like a webpage or a website. The people who created a website or webpage can instruct Google what to do if it passed by or crawled their website.
Crawlable and indexable websites are those that you find on the internet. For the room that is closed, it is like the log-in page of a website.
Google knows that it is a log in page, but cannot display what is inside that page—which means that only users who have an account can see what is inside that page.
Websites that are not crawlable are private websites. They are on the internet but Google will not show them. Instead, you can only access these websites if someone gave you a link.
How Does Google Organize Information?
So now let us give it a thought. Crawling vs. indexing: why are they important?
The crawling process involves a lot of robots that Google calls spiders. These are robots that go to various websites to visit them.
The crawling process does not always start with Google. Sometimes, web developers send Google a file called a sitemap. It is a file that tells Google about a website and its contents.
Once Google receives this file, the spiders begin to travel and visit that website. This in itself is a crawl. The other process is when Google visits a website and then sees a link there. It does not matter if this is an inbound link or an internal link.
Google will visit that page of that link, and then check if it can index it or not.
Now, once all these crawling is done, the information that the spiders got will be taken to the servers. It is in these servers that the robots organize the links and webpages, and see how they are related to each other.
This is called the indexing process.
It is during this indexing process where Google decides what the content of the webpage is, what the keywords are, how meaty the content is, and how relevant it is.
From all these data, and along with many others, Google will be able to tell how to rank a webpage, and it can decide whether to show your webpage on the top of a search engine results page or not.
It is during the indexing process where Google assesses the usage of keywords, meta-data, title tags, and all things relevant to seo.
Crawling vs. Indexing: Why Should I Know These Things?
Knowing the difference between the two is important because it helps you understand the relationship between your website and Google. There will come a time when you will begin to take your SEO to a different level.
At that point, you will get introduced to backlinks, robots.txt, and many more. If a blogger allows you to post a guest post and says that the link to your site is a no-follow, then you know what it means and you can decide whether to pursue the guest post or not.
What does a no-follow link mean? It means that the website is giving instructions to Google not to follow the link. If this is the case, Google will see the anchor text on a blog, knows that it links to some website, but it will not follow that link back to your website.
Because of that, Google will not know that your webpage related to that anchor texts exists, unless you submit it to Google yourself.
In this case, do you think it makes sense for you to pay a blog owner to post your blog? Even if it is free, it is possible that you paid someone to write that blog. In this case, it is a waste of money.
Crawling vs. indexing: the difference between the two is pretty simple. Crawling is an activity where Google just visits billions of websites and webpages every day.
To Google, each webpage is a room, and it needs permission to see what is inside that room, along with permission to show other people what is inside that room.
Indexing, on the other hand, is the process of “naming” all these webpages and organizing them inside a database. Think of how a library works. The librarian knows how the books are indexed and can tell you which aisle to find a book you are looking for.
The librarian is like Google. The librarian has to walk the library and index new books, then organize them into the shelves. By the time someone asks for it, the librarian knows where it is and can show it to the user.