encoding vs logogram

encoding

noun
  • 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. 

  • A conversion of plain text into a code or cypher form (for decoding by the recipient). 

logogram

noun
  • A character or symbol (usually nonalphanumeric) that represents a word or phrase. 

  • A kind of word puzzle: a logogriph. 

How often have the words encoding and logogram occurred in a corpus of books? (source: Google Ngram Viewer )