A keyframe stores the value of an animated property at a particular time.
A few decisions can describe a whole movement
Place a flower low at the start and higher two seconds later. Those two position keyframes describe the endpoints; interpolation determines the values between them. A keyframe can concern one property, such as rotation, rather than every part of the scene. It is not necessarily a complete rendered image saved at that moment.
Timing changes the meaning
The same pair of poses can feel calm or abrupt depending on the time between them. Adding keys everywhere is not always the answer: unnecessary keys can make motion harder to revise and increase exported animation data. Start with the moments that express the action clearly, then add detail where the movement genuinely needs it.
From a source animation to an AR artwork
When preparing an animated GLB for Painta, distinguish the keyframes inside the model from the timing of that asset within a larger experience. A character’s wave may be a two-second clip even if the model is visible for much longer. Review the first pose, last pose and transitions so the visitor does not see an unintended jump when playback begins or repeats.