the.com/characterization

means The craft of building a fictional person's personality, motives, and behavior so they feel real on the page.

from Traces back to Greek 'kharaktēr' — originally a mark stamped or engraved into metal or stone, the tool that did the stamping too. It drifted through Latin into English meaning a distinguishing mark or feature, then narrowed into 'character' as moral nature or a role in a story. 'Characterization' tacks on the Latin-style '-ize' and '-ation' to make it a process word — the act of stamping a figure with distinct, legible traits, the same way the original mark was stamped into metal.