There are mixed definitions of what pornography is but the term itself originated from Greek origins. If directly translated from its Greek origins (porna,pornae f.) + (-graphia), the literal meaning of it is “recorded or graphic description of prostitutes/whores/harlots”. Most live action pornography nowadays is literally prostitution recorded behind a camera.
Despite what some of us may often hear, pornography isn’t necessarily nudity itself (we were all born naked). There are non-sexualized or purely innocent images of nude bodies for the purpose of art. However, if an image features a nude/half-naked body that’s intentionally designed for masturbation purposes or is sexualized in a way that causes the audience to feel sexual arousal, often to the point of orgasm, then objectively it would be considered (softcore) pornography.
Perhaps the best way we can define pornography is that it is a collection of sexually explicit literature, audio, and oftentimes images, including videos, featuring sexual objectification or exploitation of human bodies (and animals) to artificially and sexually stimulate the audience for temporary sexual self-pleasure.