Redundancy is a process where a component is available in duplicate so that in case the primary component fails, the system will run on the second component that is available. You will never have to stop your activities as you have an alternate provision. In
data centers redundant hardware components could be in the form of servers, routers, switches, hard disk drives, printers, operating systems etc. The need for N+1 redundancy will mean having one more component than really required. When you have two components for example, you can move your servers to the spare one and continue business operations while the original is being repaired or undergoes maintenance. In case the component needs to be replaced you can do it without pressure. Hardware redundancy ensures business continuity even at times of hardware failure. Power outages are taken care by the automatic transfer to power backups. Hardware redundancy also allows smoother and easier processing of upgrades. Normal upgrades stop all operations and require you to go offline but with hardware redundancy you can upgrade without the need of completely stopping your operations.