You might have buy any product 4rm online shop,encryption and decryption plays a vital role in it.
If u buy any product 4rm online market,it has three stages.
1st.presales.
2nd.execution.
3rd.settlement.
Encryption and Decryption takes place at execution and settlement phase. It just converts intelligible data to unintelligible data it is encryption and unintelligible to intelligible data it is decryption.