Why the Backup Question Is Not Cloud or Local
The backup question is not cloud or local, because a single copy in either place is not a backup. The working rule is three copies of the data, on two different types of media, with one of them held somewhere else. Cloud and local are how that third copy gets off site.
Most small businesses believe they have a backup and have a synchronised copy, which is a different thing: a file deleted or encrypted on the working machine is deleted or encrypted on the sync as well. The comparison only becomes useful once that distinction has been made. What does not belong on screen is your clients' own configurations: retention windows, credentials, and where their off-site copy physically sits are exactly what an attacker would want.
Seven scenes carry the rule: one on the difference between a copy and a backup, two on what local gives and what it cannot survive, two on what cloud gives and where it is slower, one on the three-two-one rule as the actual answer, and one on the restore test almost nobody runs.

