Search Engine

What is a Search Engine?

A search engine is a service that allows Internet users to search for information and various forms of content via the World Wide Web (or “Web” for short). The interface of the search engine provides a search box where users input keywords or phrases and return a list of results in the form of websites, images, videos, or other online data that semantically matches the search query. The list of content returned is known as a search engine results page (SERP).

The SERP contains both organic search and paid search results. Organic search describes results that are naturally generated and not influenced by commercial relationships. This contrasts with paid search results, where prominence is purchased by an advertiser as a commodity.

For example, using the Google search engine to query “engineering project management software” will return a list of naturally generated results that are highly relevant to the query, along with paid results in SERPs.

The term commonly refers to web search engines but describes any system that retrieves data from large datasets based on a user’s query. This includes database or enterprise search engines for internal records and data.

How Search Engines Work

A search engine performs a number of steps to do its job. First, a bot, also called a spider/web crawler, trawls the web for content that is added to the search engine’s index. These bots scan all sections and subpages of a website, including video and images.

Hyperlinks are parsed to find internal pages or new external websites to crawl. To help bots crawl efficiently, larger sites submit an XML sitemap to the search engine that acts as a roadmap of the site itself.

Once all data has been fetched by the bots, the crawler adds it to a massive online library of all discovered URLs. This constant and recursive process is known as indexing and is necessary for a website to be displayed in SERPs. Then, when a user queries a search engine, relevant results are returned based on the search engine’s algorithm.

Search Engine Features

How Search Engines Rank Results

Early search engine results were based largely on page content. Today, proprietary algorithms are much more complex, and search results are based on hundreds of variables, weighing complex factors such as relevancy, accessibility, usability, page speed, content quality, and user intent to sort results in a certain order.

In the last few decades, a whole science called search engine optimization (SEO) was developed to ensure a website, or at least some of its pages, “scales” the ranking to reach top positions in SERPs.

How Do Search Engines Personalize Results?

Personalized results use cookies to connect user data, such as search and browsing history, to the content shown in the results. Search engines also use artificial intelligence (AI) and machine learning (ML) algorithms to find patterns in user data to personalize results.

For example, if a user frequently visits cooking blogs, search engines may prioritize those blogs for the user in future related searches. This impacts the display of PPC ads (pay-per-click) and affiliate links in SERPs, resulting in relevant ads to increase conversion rates.

Search Engine Examples

Popular crawler-based search engines, by worldwide market share, include the following:

1. Google: 91.05%
2. Bing: 3.74%
3. Yandex: 1.44%
4. Yahoo!: 1.26%
5. Baidu: 0.87%
6. DuckDuckGo: 0.6%

Other types of search engines include crowd-sourced platforms like Wiki.com, social change search engines like Ecosia and Ekoru, and software designed to search internal datasets – like databases and enterprise search systems.

Search Engines and Privacy

Search engines typically collect data to improve the platform and target advertisements. User data is collected from the moment a search query is submitted, through to clicking on search results. Tracking often continues on subsequent clicks and visited pages.

Types of user data collected include:

• Browsing history
• Browser data
• Click-through data
• Cookies
• Device information
• IP addresses
• Location data
• Search queries
• User account information
• User interactions

There are various ways to counter search engine tracking. Using a virtual private network (VPN) makes it difficult for search engines and websites to track users. Other options include enabling privacy features on web browsers, using incognito mode, or choosing a search engine that does not track browsing activities.

Future of Search Engines

The future of search is widely discussed in SEO circles but remains somewhat uncertain. Most experts agree that mobile devices and cutting-edge technologies, like generative AI search, will continue to drive change.

Other factors influencing the future of search engines include voice and conversational search, and personalized search experiences.

The Bottom Line

The search engine definition is a system that retrieves data based on a user’s query. Online, it refers to searching content via the web – a process made possible by small bots that crawl for content and add it to the search engine’s index.

Google and other search engines use proprietary, complex algorithms to rank results on hundreds of variables. However, the speed and convenience of finding information online come at a cost: most search engines collect user data and track activities. To protect your privacy, consider using a VPN, browsing incognito, or choosing a search engine that values privacy.

FAQs