The following storage media are not recommended for long-term storage:
USB thumb/flash drives
Optical discs (CD-r/DVD-r)
When your files are gathered and organized on a central computer, follow the 3-2-1 Rule when making backup copies.
After you copy your files from your main computer to your backup storage, check to make sure that the files copied without any errors. One quick way to do this is to compare the total file size of the collection to see if there's any difference between the copies. Most computers have a Get Info feature (command-I or alt-click>Get Info) that will give you the total file size in bytes.
External hard drives
Storage devices come in desktop and portable varieties from commercial manufacturers such as Seagate and Western Digital. Hard disk drives (HDDs) are reliable and cheap for the amount of storage capacity, but they have moving parts that can break. Solid state drives (SSDs) are more durable, smaller, and faster, but can be expensive. Expect to spend around $50–$100 per terabyte of storage.
Cloud storage
When you store data in the "cloud," it's actually stored on servers owned by the service provider. Consider these factors when deciding on a cloud or file-hosting service:
All digital data is encoded onto physical media which is itself susceptible to damage and degradation. For best results, digital storage media should be kept in the same kind of environmental conditions that you find comfortable: