What is a diary?

I started having a diary when I was 10. It was a simple notebook where I share my thoughts and ideas. As a little girl, I have always wanted to write the highlights of my day. This includes both happy and sad incidents. As I grew a little bit older, my diary became my secret keeper. I spent writing about boys, crushes, after school dates and a lot teenage stuff. From a simple notebook, I opted to have one that is more secure -- a journal with lock. Now that I am 30ish, I still have a diary but in a form of a planner. It is journal of the things that happened for the day featuring important events and highlights. It is a place where I keep reminders and notes that may come in handy in the future. My diary also has a lot of stickers and clippings. I also write inspirational quotes in my diary. What is really the purpose of a DIARY? A diary is important avenue for self-expression. It is like a friend that you can share everything with 24/7. There is no judgement.