Which AWS storage option offers the highest performance?

Is it possible to choose specific data to store in the snapshot?

Is it possible to update the existing snapshot with new data?

What is the persistance storage in EC2 instance?

persistent storage refers to storage that retains data even after the instance is stopped or terminated.

What is the role of dedicated instance?

Dedicated Instance is an Amazon EC2 instance that runs on hardware dedicated to a single customer. Dedicated instances ensure that your workloads are isolated at the physical host level, though they still share the same underlying infrastructure as other AWS services.