By giving crawlers a path to a page they do not know from a page they do know, internal links help search engines find pages. In other words, once a search engine crawls a certain page and finds an internal link there, it can follow the link and find the URL of the destination.
As you can see, this basic sequence describes the relation between internal links and page discovery. There is no need to find all URLs individually since they can be discovered from each other.
Page Discovery Starts With a Page Known to Search Engines
Let us consider that a search engine already knows about Page A.
While crawling Page A, a search engine finds an internal link pointing to Page B on the same website. This internal link reveals Page B as a URL to be visited by the crawler.
Here is a very simple sequence:
Known Page → Internal Link → Destination Page
Page B was not supposed to be visited initially. It was discovered due to the presence of a certain link to it from another page.
This is just one of the basic ways crawlers explore websites. Links let crawlers go beyond the page they started with and find other pages on their way.
Internal Links Provide Discovery Paths Between Pages
Just one internal link provides just one path, but the process does not end here.
From Page A, a crawler goes to Page B. Then, from Page B, the crawler may find another internal link leading to Page C. While following these connections, crawlers may discover new URLs.
However, this does not mean that crawlers follow all available links immediately. Search engines make their own crawling decisions. The main thing here for page discovery is that the links provide certain routes.
Without these routes, the search engine would have to find another way to discover the URL.
Thus, internal links serve as connectors that let the knowledge about one page lead to the discovery of another page.
A Page May Be Reachable via Several Routes
Discovery routes do not have to be a simple chain.
There may be several pages that the search engine already knows about linking to the same destination page. For example, Page A can have a link to Page D, while Page B and Page C also have internal links to Page D.
The destination is the same, but now there are several internal routes that let the crawler discover the destination URL.
This is much more natural for websites, which are not always connected in one linear sequence.
In the context of page discovery, each connection lets the crawler discover another URL.
Finding the URL Is Different from Indexing the Page
And this difference is very important, since sometimes the discussion about internal links and page discovery confuses the terms and assumes that page discovery means the indexing and inclusion of the page in search results.
Not at all!
Page discovery means awareness of the existence of the URL. While following an internal link, the crawler may find the URL, but what happens next depends on the decisions of the search engine. So, it does not necessarily mean the page will be included in the index or will be ranked in search results.
So, an internal link allows finding the URL without any guarantees of indexing.
Understanding the difference between the two stages clears things up a lot.
Internal Links Allow Crawlers to Go Beyond the Starting Page
The page discovery process is pretty simple.
Once a crawler gets to a page it knows about, it discovers links to other pages and may use them as routes to new URLs. These destinations reveal their own links, which create additional routes on the website.
Thus, internal linking provides search engines with the opportunity to go beyond the pages they know and discover pages they do not know.
This is exactly the connection between internal links and page discovery. An internal link does not guarantee that the destination page will be indexed or ranked in search results. But it does something more fundamental first. It provides the search engine with a route to the page.
