Cameras only help if the footage is still there next month. Files only help if they survive the laptop that held them.
We size PoE, uplink, and retention as one system. A 4K turret on a 1G overloaded switch drops frames; an NVR with no spare bay fails the week you add the parking lot.
The same closet can hold camera storage and a UniFi Drive or NAS share for accounting, job photos, and shared documents. We then replicate that share to cloud storage so a flood or theft is not the end of the company archive.
Indoor vs outdoor, night requirement, and whether you need AI detections or just a clean recording.
How many days of continuous or motion-based video must stay online.
Which file shares stay local, which sync to cloud, and who is allowed to export footage.