Hanzi
The Chinese characters used to write Mandarin — logograms, not letters.
Hanzi (汉字, “Han characters”) is the writing system used for Mandarin. Unlike alphabetic scripts, each character is a logogram — a unit representing a morpheme (a meaningful piece of a word) rather than a sound.
A literate adult reader of mainland Chinese knows roughly 3,500-4,500 characters. HSK 3.0 maps coverage by band: Band 1 introduces around 600 characters, Band 5 covers more than 3,000.
Many characters are compound — built from two or more component parts called radicals. 妈 (mother) combines 女 (“woman”) and 马 (“horse”) — the woman component hints at meaning, the horse component hints at sound (mǎ → mā).
Bookverse treats characters as a vocabulary, not a chore: you meet them in real chapter reading, hear them spoken, and review the ones that didn’t stick.