Several parts combine into one character.

作 is a phonetic-semantic compound: 亻 (person) + 乍 (zhà, "for a moment / suddenly" — but originally a pictograph of cutting / making with a knife). 乍 contributes both the sound and a hint of the original "making" action. The composite reads as "a person making something with the hands" = to make, to create, to compose. 作 is one of the highest-frequency characters across all CJK languages, used in countless compounds for human creative and labor activity.

Korean reading "jak." Saturates Korean vocabulary across art, labor, and academia: 作品 (jakpum, work / piece — used for art, literature, films), 作家 (jakga, author / artist), 動作 (dongjak, motion / movement / gesture), 作業 (jageop, work / task / operation), 創作 (changjak, original creative work), 農作 (nongjak, agriculture / farming work — 농작물 nongjangmul "agricultural products"). 작가 is one of the most common Korean professional titles.

Mandarin zuò, 4th tone. 作 (zuò), and the central everyday word: 工作 (gōngzuò, "labor-make" = work / job / occupation — the standard Mandarin word for "job / work"; the question 你的工作是什么? "what is your work?" is week-one Mandarin). 作家 (zuòjiā, writer), 作业 (zuòyè, "make-task" = homework / school assignment — every Chinese student lives under the weight of 作业), 作为 (zuòwéi, "as / in the capacity of" — formal preposition).

Japanese on-readings split into two. サク (saku) — 作品 (sakuhin, work / piece), 作家 (sakka, writer — note the sandhi from saku-ka to sakka), 創作 (sōsaku, original creation), 動作 (dōsa — wait, this uses サ; let me restate), 農作物 (nōsakubutsu, agricultural products). サ (sa) — 作業 (sagyō, work / operation), 作法 (sahō, manners / etiquette), 動作 (dōsa, motion). Kun-reading つくる (tsukuru, "to make") — 作る (tsukuru) — and Japanese makes a famous trio of kanji distinctions for the same kun-reading: 作る (tsukuru, "make" — small or general items: cooking, crafting), 造る (tsukuru, "build / construct" — large, structural: cars, ships, buildings), 創る (tsukuru, "create" — new, original, never-before-existing things). The choice of kanji subtly reveals the speaker's stance on what kind of making is occurring.

Memory aid: a person (亻) plus 乍 (sudden cutting / shaping with a knife) — a person actively making something = to create.