Google and other search engines have sophisticated algorithms to rank pages and sites, so satisfying these algorithms, which are not available to the public, can get a website into the top 10. However, experts have determined some of the basic factors these algorithms use.
Working on a website to improve its rank is called search engine optimization. In the past, simple algorithms would simply see how many other websites linked to the website being ranked, but abuse led to more sophisticated algorithms over time.
Newer algorithms are able to detect the quality of the content on the page itself. Well-written content, for example, can improve a site's rank. Many algorithms also reward sites that receive regular updates, so supplying fresh content can improve a website's ranking. Links to the website still help, but many algorithms focus on links from credible websites; a link from Wikipedia, for example, helps more than a link from an obscure blog.
There are also a number of smaller factors experts believe help as well. The loading speed of the page, for example, might affect a site's rank. Websites that render well on smartphone and tablet browsers are likely to rank higher than those that don't, and search engine algorithms might reward a website that links to other high-quality sources.