EBS is a kind of permanent storage in which the data can be restored at a later point. When you save data in the EBS, it stays even after the lifetime of the EC2 instance. On the other hand, Instance Store is temporary storage that is physically attached to a host machine. With an Instance Store, you cannot detach one instance and attach it to another. Unlike in EBS, data in an Instance Store is lost if any instance is stopped or terminated.

https://aws.amazon.com/premiumsupport/knowledge-center/instance-store-vs-ebs/#:~:text=Use%20the%20instance%20store%20for,use%20Amazon%20EBS%20volumes%20instead.