I found this article and enjoyed it so much I had play with some code since the numbers are small enough.
https://thatsmaths.com/2016/08/11/a-toy-example-of-rsa-encryption/
Standard Encryption's vs RSA Encryption (Public Key Encryption) Fundamental Differences
If you read that and couldn't immediately clarify the difference then let me blow your mind because its simple:
STANDARD ENCRYPTION'S:
ORIGINAL_DATA + Password(or KEY) = Encrypted DATA
Then to decrypt ->
Encrypted DATA + (SAME Password(or SAME KEY)) = ORIGINAL_DATA
RSA: