Search engine optimisation (SEO)

‘Natural referencing’ (SEO) is so called to distinguish it from ‘paid referencing’ (SEA).
SEO is short for ‘Search Engine Optimisation’.
In this context, ‘natural referencing’ means that no money has been spent to appear in search results. But that does not mean that this referencing, this ranking of our site by search engines, will progress naturally, automatically, without effort.
The virtue of natural referencing is that if you appear in the top results given by a search engine (for a given keyword, for example: ‘Provence’), you know that this is the result of the search engine optimisation work you have carried out on your website, without paying the search engine, ranked solely by the algorithm (of that search engine) according to criteria of optimisation (technical and content), relevance and quality.
Natural search engine optimisation requires work (content, technical aspects, links) and can be strategic and optimised.
Search engine advertising (SEA)

SEA stands for ‘Search Engine Advertising’. It is simply paid search engine optimisation.
SEA is different. Here, you pay to appear on the search engine results page (to which you have made your payment). As soon as you stop paying, this ‘sponsored link’ disappears. Two parameters come into play:
the budget you can invest in a keyword ‘auction’,
the quality and relevance of the advert (relevance, click-through rate, etc.).
The advert/ad appears at the top of the search engine results page, under ‘sponsored links’ (depending on the search engine chosen).
CONCLUSION
In SEA, our visibility depends on the budget and performance of the advert, whereas in SEO it is gained over time. Each method has its advantages and disadvantages, and meets specific needs.
