What cryptography is? Julius Caesar really used cryptography?

With the freedom of connectivity to multiple programs at a times comes the risk of security breach. In this regard, various techniques are applied to secure this communication. The most common and basics techniques you might have already heard of is "CRYPTOGRAPHY". You may read more about cryptography here: http://hdl.handle.net/10481/74740 DOI: 10.30827/Digibug.74740 The original video is also premiered on ReiDoCrea: https://youtu.be/MtOnNlKA7q0