1. What are the differences among Spot instance, On-Demand instance, and Reserved Instances?
All these instances are models for pricing. Spot instance powers the customers to acquire compute capacity without having any upfront commitment. The hourly rate of Spot instance is usually higher than the speed of the On-Demand instance. Both in Spot instance and On-Demand instance, the users, do not commit to any particular duration. However, there is a fixed period to which the users have to stick in the Reserved Instance.