The system deciding which results appear for a search and in what order. It changes constantly, and nobody outside Google has the full picture of how it works.
It is worth being clear that the algorithm is not one thing. It is many systems layered together, several of them machine-learned, and Google engineers themselves cannot always explain a specific ranking.
What this means practically is that anyone claiming to know exactly why you rank where you do is guessing with confidence. What is known is directional: relevance, quality, links and usability all matter, and the weighting shifts.
This comes up most often in Search Engine Optimisation. Getting found when someone searches for what you sell — without paying per click. Slower than ads, but it compounds and keeps working after the budget stops.
A free consult is twenty minutes and there is no pitch deck at the end of it.