FPS (frames per second) is how many images a camera captures and records each second, and it directly shapes both motion smoothness and the storage bill. Cinematic smoothness is around 25–30 fps; surveillance often records lower — 12–15 fps is common for general coverage — because most scenes do not need full motion and every extra frame costs bandwidth and disk.
The right frame rate is a function of the job, not a single best number. Fast action needs high fps: a licence-plate camera on a highway or a casino table where sleight-of-hand matters may need 25–30 fps (or more) to avoid motion blur between frames. A corridor or a stockroom is fine at 6–12 fps. Because storage scales roughly linearly with frame rate, halving fps on cameras that do not need motion roughly halves their recording cost.
The pitfall is setting one global frame rate for every camera. Recording an entire site at 30 fps "to be safe" can double or triple storage versus a per-camera rate matched to each scene, with no investigative benefit on the static views; conversely, dropping a plate or cash-handling camera to 8 fps to save space can blur the exact frame an investigation needs. Frame rate is a per-camera decision, set against the cost of a miss.
