From Latin 'captura' (a catching), from 'capere' (to take, seize) — the most transparent heir of Latin's central taking verb.
To take into one's possession or control by force; the act of seizing or catching.
From Middle French capture (a taking, a catching), from Latin captura (a catching, a taking of prey), from captus, past participle of capere (to take, to seize, to grasp, to contain). The PIE root is *keh2p- (to grasp, to seize). Latin capere was extraordinarily productive and generated an enormous Latin-derived family in English including capable, capacity, captive, caption
The word 'caption' — the text under an image — comes from the same Latin root. In legal Latin, 'captiō' meant 'a taking' or 'a seizing,' and 'caption' originally referred to the heading of a legal document that authorized an arrest or seizure. The sense of text accompanying an image developed from this legal heading usage.