150 digital marketing terms, defined without the jargon.

Digital marketing runs on abbreviations, and most of them are explained by people who assume you already know. This is a full rewrite for 2026: search has changed since the first edition, and a growing share of buyer questions now get answered inside an AI response before anyone reaches a website. Every original definition has been reviewed and brought up to date, the terms that had stopped earning their place have been retired, and fifty new ones added.

The search fundamentals are still here — SEO, SEM, keywords, search intent, SERPs, featured snippets, on-page and off-page optimisation, domain authority, schema markup, canonical tags, sitemaps and keyword stuffing. Alongside them is a full new section on AI search: GEO and AEO, the practice of getting a business cited inside an AI-generated answer rather than ranked in a list of links, plus AI Overviews, AI crawlers, llms.txt, retrieval-augmented generation and the difference between a citation and a brand mention.

There is a glossary within the glossary for AI itself — prompt, prompt engineering, token, context window, hallucination, agentic AI and human in the loop, the vocabulary a team needs just to have a sensible conversation about the tools it is using. Then the advertising terms: PPC, CPA, CPC, CTR, ROI and ROAS, quality score, bid strategy, Performance Max, lookalike audiences and retargeting.

Content and brand cover demand generation, digital PR, short-form video, influencer marketing, social listening and user-generated content. The funnel and B2B section runs from TOFU through BOFU, with account-based marketing, ideal customer profiles, buying groups, intent data, CAC and LTV, and the CRM and marketing automation platforms that hold it together. The last section is the plumbing: first-party and zero-party data, consent mode, server-side tracking, GA4, attribution models, and the website terms that come up in any technical conversation — UX, wireframes, broken links, 301 redirects, CDN and DNS.

It is written to be kept rather than read straight through. Print it, bookmark it, or forward it to whoever has just inherited the marketing.