SEO: Complete Definition and Guide

What is SEO?

SEO, or Search Engine Optimization, encompasses all the techniques, strategies and best practices for improving a website's visibility and ranking in the organic (unpaid) results of search engines, primarily Google, which accounts for over 90 % of searches in Europe.

SEO is a constantly evolving discipline. Google's algorithms are updated hundreds of times a year, and practices that worked five years ago may now be obsolete or even penalising. Today, SEO extends beyond traditional search engines: with the rise of generative AI (ChatGPT, Gemini, Perplexity), a new discipline has emerged, GEO (Generative Engine Optimization), which KERN-IT integrates into its overall visibility strategy.

At KERN-IT, the KERNWEB division approaches SEO as both a technical and strategic pillar of every web project. Wagtail CMS, combined with an optimised Django architecture, provides a solid technical foundation for search ranking: clean URLs, automatic sitemaps, structured metadata and optimal server performance.

Why SEO matters

SEO is the most powerful and cost-effective organic acquisition channel over the long term. Unlike SEA (paid advertising), SEO results persist and compound over time.

• Qualified, free traffic: SEO attracts visitors actively searching for solutions, products or information. This traffic is highly qualified and costs nothing per click, unlike advertising campaigns.
• Credibility and authority: users trust organic results more than paid advertisements. Appearing on Google's first page reinforces a brand's perceived credibility and authority.
• Long-term ROI: well-optimised content continues generating traffic for months, even years. SEO investment is cumulative: each optimised page strengthens the entire site.
• GEO visibility: with the rise of AI-based answer engines (ChatGPT, Perplexity), SEO is evolving towards GEO. KERN-IT is ahead of the curve, implementing llms.txt files on its sites to help AI agents understand and cite content in a structured manner.
• Sustainable competitive advantage: a solid SEO strategy creates a barrier to entry that competitors find difficult to replicate.

How it works

SEO rests on three complementary pillars that must be worked on simultaneously to achieve lasting results.

Technical SEO concerns the site's infrastructure: loading speed (Core Web Vitals), URL architecture, semantic HTML markup, XML sitemap, robots.txt, HTTPS certificate, schema.org structured data and accessibility. At KERN-IT, these elements are natively integrated into every Wagtail project: the Django framework generates clean HTML, Gunicorn behind Nginx ensures optimal response times, and sitemaps are generated automatically.

On-page SEO focuses on optimising each page's content: keyword research, writing optimised titles and meta descriptions, structuring content with H1-H6 tags, building internal links between pages and optimising images (alt text, compression, WebP format). Wagtail CMS facilitates this work with built-in SEO fields and StreamField blocks that enable fine-grained content structuring.

Off-page SEO covers external signals: backlinks (links from other sites), brand mentions, social media presence and online reviews. Backlink quality far outweighs quantity: a single link from an authoritative site is worth more than a hundred links from low-quality sites.

Concrete example

The KERNWEB team at KERN-IT supports a Belgian B2B services company with its SEO strategy. The site, built on Wagtail CMS, initially generates 500 organic visits per month. The goal is to reach 5,000 monthly visits within 12 months.

Phase one is a comprehensive technical SEO audit: fixing indexing errors, optimising Core Web Vitals (LCP drops from 4.2s to 1.8s through image optimisation and lazy loading), implementing schema.org across all pages and creating a multilingual sitemap.

Phase two is the content strategy: identifying 50 strategic keywords, creating 30 optimised blog posts and establishing internal linking between service pages and articles. Each article is structured with relevant H2/H3 headings, lists, optimised images and contextual internal links.

Phase three integrates GEO: implementing llms.txt and llms_full.txt files to provide AI agents with a structured view of the site's content. Articles are written with a clear structure (question/answer) to maximise the chances of being cited in AI-generated responses.

Result after 12 months: 6,200 monthly organic visits, 15 keywords on Google's first page and regular presence in Perplexity and ChatGPT responses for sector-specific queries.

Implementation steps

1. Technical audit: analyse the site's technical health with Lighthouse, Google Search Console and tools like Screaming Frog. Fix critical errors first.
2. Keyword research: identify relevant queries for the business by analysing search volume, competition and search intent.
3. On-page optimisation: optimise each target page with a unique title, an engaging meta description, a logical H1-H6 structure and quality content.
4. Internal linking: build a strategic internal link network connecting pages to distribute authority and guide users.
5. Structured data: implement schema.org markup to enrich search results (rich snippets) and help engines understand content.
6. Content strategy: regularly publish quality content that answers user questions and targets strategic keywords.
7. GEO optimisation: prepare content for AI answer engines by structuring information clearly and implementing llms.txt files.
8. Monitoring and iteration: measure results with Google Search Console and Google Analytics, then adjust the strategy based on data.

Related technologies and tools

• Wagtail CMS: a Django CMS offering native SEO features (metadata, sitemaps, clean URLs) and optimal server performance.
• Google Search Console: a free Google tool for tracking indexing, search performance and technical errors.
• Lighthouse: an automatic audit tool for measuring performance, accessibility and SEO best practices.
• Schema.org: a structured data vocabulary used to enrich search results and support GEO.
• llms.txt: a reference file for AI agents, implemented by KERN-IT to optimise visibility in generative answer engines.

Conclusion

SEO remains the most powerful organic acquisition lever on the web, but it is evolving rapidly. To the three traditional pillars (technical, on-page, off-page), GEO is now added, preparing sites to be visible in AI-generated responses. At KERN-IT, the KERNWEB division combines classic SEO expertise with an innovative GEO approach, leveraging Wagtail CMS and an optimised technical architecture to deliver maximum visibility for its clients.