What is Symmetric Key Encryption

This topic is created based upon Steven Gordon’s Tutorials about Cyber Security (https://www.youtube.com/channel/UCu1lQtQ7SJU27bRlL6hzr9A).

Suppose we live in ancient times where internet, post or any communication media was not available. If I have got a secret one day and only wanted to share that with my closest friend, the only way to achieve this is to visit my friend in person. Again, this is a…