The essence is really the most important aspect of something. It is what makes it it.
You can talk about essence when describing a very important feature of a problem, a team, the core goals or raison d’être of a company or school.
You will find many more examples on the Oxford Learner’s Dictionary online: https://www.oxfordlearnersdictionaries.com/definition/english/essence?q=essence
- The essence of the matter is that we must show our good will.
- Its ability to make you feel is the essence of this painting.
- The essence of drama is conflict.