AWS is a comprehensive, evolving cloud computing platform. EC2 is a service that allows to run application programs in the computing environment. The EC2 can serve as a practically unlimited set of virtual machines. Amazon provides a variety of types of instances with different configurations of CPU, memory, storage, and networking resources to suit user needs. Instance types are grouped into families based on requirement. These groups include: general purpose, compute-optimized, instances type, memory optimized, storage optimized and micro instances. Instances are created from Amazon Machine Images (AMI). The machine images are like templates that are configured with an operating system and other software, which determine the user’s operating environment. Users can select an AMI provided by AWS, the user community, or through the AWS Marketplace. Users can also create their own AMIs and share them. While creating instance on Cloud Lab sometimes authorization error occurs it can be : Geographical region- set it as US East(N. Virginia). Cache memory- clear it. as well as try opening through different browser or incognito window.