Given your query, Google’s ranking algorithm determines which results to deliver and their ranking on the search engine results page.
Changes
2010: Caffeine
- Major rewrite
- Emphasis on freshness of articles
- Find pages sooner after publication
2011: Panda
- Eliminate poor quality results
2012: Penguin
- Targeted link schemes (buying backlinks from shady sites) and keyword stuffing (repeating keywords to manipulate rank)
2013: Hummingbird
- Attempt to better match results to searcher intent by evaluating context
- Number of words in search increased. People ask questions to Google.
2016: Possum
- Local
2018: Mobile-first
- Mobile version became starting point for determining ranking