RAIDs and JBODs are both pieces of technology for storage. Besides that there are considerable differences between the two.
A RAID is a redundant array of independent disks. Based on the way you configure your RAID array you can see improvements in read/write performance or provide yourself with data protection using parity data and fault tolerance in the event of a drive failure. A RAID takes multiple disk and spreads data across them which is what provides the speed and security boosts.
A RAID is typically used when you need data protection and on mission critical servers.
A JBOD is fairly simple, short for 'just a bunch of disks'. This storage technology is a housing for adding additional drives to your storage system. JBODs do not provide any data protection because your data is on individual disks stored within the JBOD, if a drive fails that data is lost.
JBODs are typically used as a backup for your main storage.