Hibernate helps to power down PC without closing down all applications and works you performing on it for easy continuation when next you wakeup your PC
1. Press the Window + letter W buttons and your system Settings Search Menu comes up. Then type "Power"
2. Click on change what the power buttons do.
3. Click change Setttings that are currently unavailable
4. Scroll down till you see the Shutdown settings section and mark the checkbox infront of Hibernate.
5. Click on Save Changes and you are done.
From now on you would find the hibernate shortcut on your PC Power Menu Option.
For Windows 10 users watch the video below to know how to show hibernate on start menu: