True SEO School https://validator.w3.org/feed/docs/rss2.html  SEO Fundamentals. Course description Lesson 7. What is SEO experiment? Home Lesson 1. What is SEO and where lies its limit? Lesson 6. The goal of SEO Lesson 5. The method of SEO. Two levels of optimisation Lesson 4. What data does SEO use? Lesson 2. SEO-specific perspective Lesson 3. What is the source knowledge in SEO? About