Firstly let talk about Amazon Web Services:
Customers can create their own Amazon Machine Images (AMI) containing an operating system, applications, and data, and they control how many instances of each AMI run at any given time. Customers pay for the instance-hours (and bandwidth) they use, adding computing resources at peak times and removing them when they are no longer needed.
Amazon provides five different types of servers ranging from simple-core x86 servers to eight-core x84_64 servers. Customers do not have to know which servers are in use to deliver service instances. They can place the instances in different geographical locations or availability zones. Amazon allows elastic IP addresses that can be dynamically allocated to instances.
With CC, companies can scale up to massive capacities in an instant without having to invest in new infrastructure, train new personnel, or license new software. CC is of particular benefit to small and medium-sized businesses who wish to completely outsource their data-center infrastructure, or large companies who wish to get peak load capacity without incurring the higher cost of building larger data centers internally. In both instances, services consumers use what they need on the Internet and pay only for what they use.
CC evolves from grid computing and provides on-demand resource provisioning. Grid computing may or may not be in the cloud depending on what type of users are using it. If the users are systems admin and integrators, they care how things are maintained in the cloud. They upgrade, install, and virtualize servers and apps. If the users are consumers, they donot care how things are run in the system.
Similarities and differences
They are both scalable. Scalability is accomplished through load balancing of application instances running separately on a variety of operating systems and connected through Web services.
Both of them involve multitenancy and multitask, meaning that many customers can perform diff tasks, accessing a single or multiple apps instances. Sharing resources among a large pool of users assists in reducing infrastructure costs and peak load capacity.
The Amazon provides a Web services interface for the storage and retrieval of data in the cloud. Setting a maximum limits the number of objects you can store. You can store obj as small as 1 byte and as large as 5GB or even several terabytes. While the storage computing in the grid is well suited for data-intensive storage, it is not economically suited for storing abjects as small as 1 byte. In a data grid, the amounts of distributed data must be large for maximum benefit.