An index refers to the database utilized by search engines to store information about websites. If a website isn't in this index, it won't appear in search results.
Google's index data determines the value of search terms and keywords. Search engines use algorithms to analyze this data, considering factors like frequency and relevance. The index includes URLs and all associated content such as text, images, and videos.
This analysis informs Google's algorithm to assess which content best meets user intent. Google search results and rankings are then derived from this content evaluation.
Global search engines like Google maintain separate indexes for each market, such as the US (google.com) and Japan (google.co.jp). These national indexes tailor results to the specific behaviors and preferences of users in each country, offering more accurate and relevant information.
While many global companies have prominent websites across multiple country indexes, understanding different ranking factors in each market is crucial. Each national index has unique keyword data, essential for informed SEO and content marketing strategies.
Local search engine indexes operate similarly to country indexes but on a smaller scale, such as a city or region. They are crucial for local services or places, offering location-specific information. For example, a search for "pizza near me" in Miami will yield different results than in Portland.
The local indexes for Miami and Portland show distinct results for "pizza near me".
The search market is dynamic, requiring continuous indexing and re-indexing by search engines to provide relevant information. As new websites and content emerge, search engines must regularly update their indexes. A new page might not rank if it hasn't been included in Google's index yet.
Websites not included in the index won't appear in search results. Ensuring that Google can crawl your website is essential. This involves making the domain technically accessible so that crawlers can view all pages and content, enabling their inclusion in the index.
Traditionally, search engines relied on desktop crawlers for indexing. However, a 2016 Google blog post announced a shift to mobile-first indexing, meaning the primary index will be based on mobile versions of websites. This change highlights the need for webmasters to stay updated with Google's indexing practices, as these determine a website's ranking performance.