磁盘
cí pán · HSK 7
(computer) disk
💿 磁 magnet + 盘 plate = a magnetic plate, i.e. a disk
cí means magnet or magnetic, pán means tray or plate. A hard drive is literally a magnetic platter that stores data — magnet-plate is exactly what the hardware is.
盘 — 舟 boat (phonetic) + 皿 dish (meaning)
Originally written 槃 with 木 wood, depicting a wooden tray or basin. The modern form 盘 keeps 皿 (dish/vessel) as the meaning component and uses 舟 as a phonetic hint. From 'flat tray' it extended to 'plate,' 'coil/wind around,' and 'examine.'