SEO Glossary Part 2: AI to Bing

Second entry in the running SEO glossary, continuing straight through the alphabet from “artificial intelligence” to “Bing.” As with Part 1, treat each entry as a standalone reference definition rather than a strategy playbook.

Artificial Intelligence (AI)

In an SEO context, artificial intelligence refers to machine-learning systems that perform tasks historically requiring human judgment, such as evaluating relevance, understanding language, and predicting what a searcher actually wants. Google’s ranking systems now incorporate multiple AI components, including RankBrain (introduced 2015), BERT (2019), and the large-model systems that followed them, MUM (2021) and, more centrally by 2026, the Gemini family, which now inform features such as AI Overviews and the broader AI Mode search experience.

The practical shift is that these systems learn patterns from enormous volumes of query and engagement data rather than executing an explicit, human-written rule set. That makes reverse-engineering a specific ranking behavior far harder than it was in the PageRank-only era, because there often isn’t a single discrete rule to find, only a learned weighting that even Google’s own engineers can’t always fully explain in plain language. AI Overviews, which place a generated answer above traditional organic results for many queries, and AI Mode, Google’s fuller conversational search experience, are the most visible examples of how this shift changes click behavior, since a satisfying AI-generated summary or answer can reduce the need to click through to any single source at all.

For content strategy, this shift has a practical consequence worth naming directly: being cited as a source within an AI-generated answer and ranking in the traditional organic results below it are not the same outcome and don’t necessarily move together. A page can be pulled into an AI Overview’s summary while still losing the click it would have earned from a traditional blue link, which is why publishers and SEO teams increasingly track AI-answer citation and visibility as a separate metric from conventional ranking position rather than assuming one implies the other.

Authority

Authority describes the cumulative trust and credibility signals search engines associate with a site or page when deciding how to rank it, built from things like the quality of sites linking to you, a consistent track record of accurate content, positive engagement, and technical reliability.

It’s worth separating this general concept from “Domain Authority,” a specific third-party metric built by Moz on a 1-100 logarithmic scale. Moz’s own metric is explicitly modeled on the idea of authority but is not something Google itself uses as a ranking input; Google has stated plainly that it doesn’t use Domain Authority or any equivalent single third-party score. New domains generally start at a disadvantage regardless of content quality simply because they haven’t yet accumulated a track record, and authority built for one topic doesn’t automatically transfer to an unrelated one, which is part of why topical focus tends to outperform broad, unfocused expansion.

This is also why chasing a higher third-party authority score as an end in itself tends to be a weaker strategy than it looks. A site can raise a metric like Domain Authority by acquiring links in bulk from unrelated, low-relevance sources and still see no meaningful ranking improvement, because Google’s own evaluation of authority weighs topical relevance and genuine trust signals in ways a single logarithmic third-party score doesn’t capture.

Author Authority

Author authority is the idea that search engines might factor the credentials and track record of a specific writer into how content ranks. Google actually tested a version of this directly: Google+ authorship markup, rolled out in 2011, let authors link their byline to a Google+ profile that could then surface alongside search results. Google discontinued the program in 2014, and there’s no public, confirmed evidence that author identity functions today as a direct, isolated ranking signal.

That doesn’t make the underlying concept irrelevant. Google’s E-E-A-T guidance for its human quality raters explicitly asks about the expertise and experience behind content, particularly for topics that affect health, finance, or safety, and a credible, consistently bylined author remains a legitimate trust signal for readers even without confirmation that it functions as a discrete algorithmic input.

Some SEO vendors market author-authority optimization services implying a direct, measurable ranking boost from author credentials alone; that claim outruns the actual evidence. The more defensible framing is that a genuine author bio, real credentials, and a consistent publication history support a reader’s trust in the content and contribute to the broader E-E-A-T impression a page makes, without a confirmed, isolated mechanism translating “author has X credential” into “page ranks Y positions higher.”

B2B (Business-to-Business)

B2B describes commercial relationships where one business sells to another business rather than to an individual consumer. Search behavior in B2B contexts tends to involve longer buying cycles, often spanning several months, multiple stakeholders who each search for different angles of the same decision, and more technical, specification-driven content needs than consumer search typically requires. Conversion in B2B contexts is usually a qualified lead rather than a direct purchase, which changes how success gets measured against organic traffic. Content strategy for B2B search generally needs to address several distinct roles within a single buying committee, since the person searching for pricing information, the person researching technical specifications, and the person who ultimately signs off on the purchase are often three different job titles with three different questions, even when they all eventually influence the same decision.

B2C (Business-to-Consumer)

B2C describes commercial relationships where a business sells directly to individual consumers for personal use. Compared to B2B, B2C search tends to involve shorter consideration windows, sometimes resolving within a single session, individual rather than committee decision-making, and messaging that leans more on price, convenience, and emotional appeal than on technical specification. Consumer search volume also tends to be substantially higher in aggregate than B2B equivalents, simply because the buyer pool is much larger. Mobile search plays a proportionally bigger role in B2C than in B2B as well, since consumer purchase decisions are more likely to originate from a phone in a moment of immediate need, which raises the practical stakes of mobile page speed and usability for B2C sites relative to B2B sites where research often happens on a work desktop across multiple sessions.

Backlink

A backlink is a hyperlink from one website to another. Search engines have long used backlinks as one signal of a page’s credibility, treating a link roughly as an editorial vote of confidence, though the value of any individual link depends heavily on the linking site’s own authority, topical relevance, and whether the link sits in genuine editorial context versus a footer or paid placement.

Corrected timeline: the nofollow-related attribute system did not change in a single 2020 event. Google announced two new link attributes, rel="sponsored" for paid or advertising links and rel="ugc" for user-generated content links such as comments, on September 10, 2019. At the same time, Google announced a separate, later change to how all rel attributes, including the original nofollow, are treated for crawling and indexing purposes: rather than being an absolute directive to ignore a link, nofollow, sponsored, and ugc all began functioning as hints Google may or may not follow, effective March 1, 2020. So the accurate sequence is two stages: the new attributes were introduced in September 2019, and the hint-based treatment took effect roughly six months later, in March 2020, not as one combined 2020 event.

Baidu

Baidu is China’s dominant search engine, incorporated on January 18, 2000 by Robin Li and Eric Xu. It remains the largest search platform in mainland China, though its share of Chinese search traffic has been reported anywhere from roughly 40% to the mid-60% range across recent measurements, reflecting real month-to-month volatility in that market rather than a single stable figure, so any specific percentage should be treated as a snapshot rather than a fixed constant.

Baidu operates under different rules than Western search engines: content must comply with Chinese government censorship requirements, sites generally need Internet Content Provider (ICP) licensing to rank well, and hosting on servers located in mainland China carries a real advantage. Meta keywords, largely irrelevant to Google since the early 2000s, still reportedly carry some weight in Baidu’s ranking system.

Bing

Bing is Microsoft’s search engine, launched in June 2009 as a successor to Microsoft’s earlier Live Search and MSN Search products. As of 2026, Bing’s global market share sits in roughly the low-to-mid single digits by direct query share, though that figure understates its actual reach since Bing also powers Yahoo search results and provides the underlying search index behind Microsoft Copilot.

Practically, Bing differs from Google in a few consistent ways: it has historically leaned more on exact keyword matching and less on deep semantic interpretation, and multimedia content has tended to receive more prominent placement in its results. Bing Webmaster Tools provides its own indexing and performance data separate from Google Search Console, and sites that want visibility across both major Western search ecosystems generally need to submit and monitor each independently.

Quick reference

Term	One-line definition
Artificial Intelligence (AI)	Machine-learning systems now embedded in Google's ranking and answer generation
Authority	Cumulative trust/credibility signals a site or page has accrued
Author Authority	Trust signals tied to a specific named author, not just the site
B2B	Business-to-business, one company selling to another
B2C	Business-to-consumer, a company selling directly to individual buyers
Backlink	A link from another site pointing to yours
Baidu	China's dominant search engine
Bing	Microsoft's search engine, also powers Yahoo search and Copilot

Sources cited: Google Search Central: Evolving “nofollow” (September 2019 announcement), Baidu company history, Wikipedia