Converting Data So It Can Be Sent Secretly
Puzzle 4 of Hellos and Goodbyes Easy Pack
Question is: Converting Data So It Can Be Sent Secretly
and the answer is: ENCODING
Word Meaning:
ENCODING — (computing) The way in which symbols are mapped onto bytes, e.g. in the rendering of a particular font, or in the mapping from keyboard input into visual text.
Definitions from Wiktionary.