Google just completed main adjustments to its rater guidelines to factor the mobile domain, recognizing that users apply searching differently when using internet-connected devices all the time. The update can be found here (PDF)
Content & Links (content and links going into your site) are two of the most Important ranking signals & RankBrain has been announced as the third most important. Page relevance & quality issues considerably impact web page rankings.
Some of the chief important ranking factors summary
1. Backlinking is the number one factor significant in effecting search ranking.
2. Site Authority plays a major role in page ranking.
3. Dedicated relative content improves ranking.
4. Longer unique quality content ranks higher.
5. Websites that are using HTTPS are doing superior to those that are matching websites using HTTP.
6. Image used in content increases ranking.
7. Connection with title tag keyword optimization & ranking.
8. Website speed is now playing a huge role in ranking signal. It does matters a lot.
9. Exact matching anchor text has a very strong impact.
10. Low bounce rate (give users reasons to move around your website) users improves ranking.
11. Mobile-Friendliness & Responsive Websites, also improves user experience.