What are the 5 important concepts of SEO?

What are the 5 important concepts of SEO?
Image result for some basic seo techniques
Through the remainder of 2021, it is essential to understand these five critical SEO concepts as we gear up for success.
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Some of the key things to focus on include:
1. The mobile experience.
2. Image compression.
3. Informational page content.
4. Site speed and technical structure.
5. Backlinking