SEO: search engine optimisation

SEO (Search Engine Optimisation) is the set of techniques and practices aimed at improving a website's visibility in the organic (unpaid) results of search engines such as Google, Bing or DuckDuckGo. The goal is to appear as high as possible for searches relevant to the target audience.

SEO combines technical factors (page speed, structure, security), content factors (relevance, quality, depth) and authority factors (external links, domain reputation). Google evaluates hundreds of signals simultaneously to decide the order of results.

History & evolution

SEO emerged shortly after the first search engines in the 1990s. Altavista, Yahoo and later Google indexed web pages, and webmasters quickly discovered that manipulating keyword density or meta tags could improve rankings.

Google changed the game in 1998 with the PageRank algorithm, which valued the quality and quantity of inbound links. The Panda (2011) and Penguin (2012) updates penalised low-quality content and link manipulation tactics, forcing a shift towards quality SEO.

Today, with artificial intelligence entering search engines, SEO is evolving towards optimisation for AI-generated answers, where clarity, topical authority and content structure matter more than ever.

Best practices

Good organic ranking requires working simultaneously on several areas:

Quality content and topical depth. Google rewards pages that fully satisfy the user's search intent. Create original, structured and up-to-date content that demonstrates authority on the topic.

Solid technical SEO. Page speed (Core Web Vitals), clean URL structure, XML sitemap, structured data (Schema.org), optimised mobile version and HTTPS are foundational requirements.

Keyword research and strategic use. Identify your audience's real searches. Prioritise long-tail keywords: less competitive and with clearer search intent.

Domain authority building. Inbound links from relevant, quality sites remain a fundamental trust signal. Earn them by creating content worth linking to.

Use cases

SEO is relevant for any web project seeking organic visibility. A blog or media outlet that optimises its articles can multiply organic traffic to tens of thousands of monthly visits with no advertising budget. An online store that invests in SEO for product and category pages reduces dependence on paid ads and improves long-term profitability.

For local businesses, local SEO (Google Business Profile, geographic keywords) is key to attracting nearby customers. In B2B, ranking for informational searches allows attracting potential clients in the early stages of the buying process.

Curiosities

  • Google updates its search algorithm thousands of times per year. Some major updates can re-rank millions of pages within hours.
  • The first organic result on Google receives on average 27–30% of all clicks on the first page, while the tenth result receives less than 1%.
  • The term "SEO" was coined by Bob Heyman and Leland Harden around 1997, although search optimisation practices existed one or two years earlier.
  • 15% of the searches Google receives every day are completely new — never seen before. This makes it impossible to optimise for every possible query.