Several parts combine into one character.

Compound character: 口 (mouth, originally a round shape) sitting above 貝 (originally 鼎, a three-legged vessel). The original meaning was "round / encircling rim of a vessel". Over time the meaning shifted from "the circle around" to "people gathered around" → members / personnel. The 〜員 suffix is one of the most productive in CJK languages — anything that's a defined "member" of a group uses it. Three forms: 繁體 員 / 新字体 員 / 简体 员.

Mandarin: yuán, rising 2nd tone (simplified 员). The 〜员 suffix names countless professional roles: 服务员 (fúwùyuán, server / waiter), 售货员 (shòuhuòyuán, salesperson), 演员 (yǎnyuán, actor / actress), 运动员 (yùndòngyuán, athlete), 公务员 (gōngwùyuán, civil servant), 党员 (dǎngyuán, party member). Also 人员 (rényuán, personnel — bureaucratic), 成员 (chéngyuán, member of a group), 委员 (wěiyuán, committee member). The 员 suffix is the standard Mandarin way to derive a job title from any work context.

Japanese: on-reading イン (in) is dominant, and the 〜員 suffix is equally productive — 会社員 (kaishain, company employee — the iconic Japanese "salaryman" identity), 店員 (ten'in, store clerk), 駅員 (ekiin, station attendant), 公務員 (kōmuin, civil servant), 議員 (giin, legislator / Diet member), 全員 (zen'in, all members), 委員 (iin, committee member), 教員 (kyōin, teacher / faculty). Mastering the 〜員 suffix lets a Japanese learner derive professional vocabulary on demand.

The Japanese 会社員 (kaishain) — "company person / salaryman" — is the postwar archetype of Japanese masculine identity, immortalized in countless films, novels, and salaryman manga.

Memory aid: a circle of people around a vessel — group members. The 〜員 suffix names every role in a hierarchy.