The 3-2-1 backup rule helps to ensure the maximum levels of data protection are provided for any data which has is being backed-up. This rule works by ensuring that at least 3 copies of any important data are always kept available, across at least 2 different storage mediums, with at least 1 copy of the data stored off-site and away from the original device being backed-up. For example, backing up a computer locally to an external hard drive whilst also backing-up a second copy of the data to a cloud storage service would meet the 3-2-1 backup rule and ensure that the data is afforded a very high level of protection.