What does encrypted means?

Answer 1

'Encrypted' means that the data had been converted into an incomprehensible format to prevent unauthorized access to it.

Answer 2

It allows me to turn this:
W~oof?Qzh?Fz~m?-/.'
into this:
Happy New Year 2018
with this program:
https://code.sololearn.com/cNmwSsxHq90l

Answer 3

The data encrypted is useless to anybody that doesn't have the decryption key.