An ideogram was a graphic character that represented an idea, and the use of ideograms in a written language was known as ideography. A pictogram was a type of ideogram that resembled the idea represented.
While translating the Osaarian cargo manifest acquired in 2153, Hoshi Sato discovered a symbol whose ideography she recognized from a piece of the Xindi probe that crashed on Earth. During her initial analysis, she found at least three of the symbols to be an exact match. (ENT: "Anomaly")