What is Disaster Recovery?

Run this mental stress test: your company's server died overnight — fire, flood, ransomware, it hardly matters which. How long until you can invoice again, and how much data is gone for good? Disaster recovery is the discipline that turns the answer from "no idea, hopefully soon" into two numbers the business has consciously accepted: RTO, how quickly systems come back (hours? days?), and RPO, how old the restored data may be (the last 15 minutes? yesterday?). Around those two figures the plan takes shape: backups kept in a separate location, standby infrastructure (anything from "we restore into the cloud if needed" up to mirrored systems already running), written procedures — who does what, in which order, with which passwords — and, crucially, rehearsal: a plan untested for a year is fiction. Because cost climbs steeply with ambitious numbers, sensible sizing starts on the business side: one hour of downtime costs the company a known amount, and the worthwhile investment follows from there. For a smaller firm, the reasonable package is surprisingly affordable — tested off-site backup, rebuild documentation and one annual drill — less than a car insurance policy, for the asset the whole company runs on.