Google says its "algorithms relies on more than 200 unique signals or 'clues' that make it possible to surface what you might be looking for."
These signals, according to Google, include things like the specific words that appear on sites, freshness of content, a company's region and PageRank. Backlinko put together an infographic listing these factors and more. Recently, Backlinko explained each of the current factors, as well.
How Long Does it Take to Rank in Google?