1. It is a phrase used to describe a varietyof computing concepts that involve a large number ofcomputers connected through a real-timecommunication network such as the Internet.In science, cloud computing is a synonymfor distributed computing over a network, and meansthe ability to run a program or application on manyconnected computers at the same time.In common usage, the term "the cloud" is essentially ametaphor for the Internet. 2. IT PROVIDES BASICALLY THREE TYPES OF SERVICES :1. SAAS2. PAAS3. IAAS 3. INFRASTRUCTURE AS ASERVICEIn the most basic cloud-service model, providersof IaaS offer computers physical or (more often)virtual machines and other resources.IaaS clouds often offer additional resources suchas a virtual-machine disk image library, raw(block) and file-based storage, firewalls, loadbalancers, IP addresses, virtual local areanetworks(VLANs), and software bundles 4. PLATFORM AS A SERVICEIn the PaaS models, cloud providers delivera computing platform, typically includingoperating system, programming languageexecution environment, database, and webserver. Application developers can develop andrun their software solutions on a cloud platformwithout the cost and complexity of buying andmanaging the underlying hardware and softwarelayers. 5. COST EFFICIENT ALMOST UNLIMITED STORAGE BACKUP AND RECOVERY AUTOMATIC SOFTWARE INTEGRATION EASY ACCESS TO INFORMATION GLOBALIZE OUR WORK STREAMLINE PROCESS IMPROVE FLEXIBILITY 6. SECURITY AND CONFIDENTIALITYSince technology has started to expand in theexponential ways we are seeing in this day andage, cyber-crime has become a concerningissue. Cloud computing does pose the risk ofincreased security threats. While mostcompanies have an up-to-date virus database,this does not make the files and informationstored in the cloud immune to hackers. 7. LESS CONTROLBy using this technology you risk losing a levelof control over your company. While many ITmanagers are experimenting with various waysof implementing an in-house cloud system thatruns on delivered metered services, this is notalways the most lucrative business move.TECHNICAL ISSUESthis technology is always prone to outages andother technical issues. Even the best cloudservice providers run into this kind of trouble, inspite of keeping up high standards ofmaintenance. Besides, you will need a very goodInternet connection to be logged onto the serverat all times. You will invariably be stuck in case ofnetwork and connectivity problems. 8. Like any new technologyadvancement, cloud computingalso creates disruptivepossibilities and potential risks. The fact that cloud computinginvolves the aggregation ofcomputing power, and moreimportantly, information, hasbecome a source of increasingconcern. 9. The top favorite among CSPs was,quite unsurprisingly, Amazon.Amazon offers a vast spectrum ofcloud services with itsinfrastructure, called Amazon WebServices. This includes offeringsuch as EC2 compute, S3 storageand so on.Google is yet another cloudprovider which has found its wayright to the top of the heap.Offering several features andfunctionality, the search giantsCompute Engine (GCE) forms thevery essence of its cloud services.What GCE lacks in a managementconsole, it makes up in speed. 10. Yet another top contender, againunsurprisingly, is Microsoft, whichis now emerging as a formidableCSP. The company is unique, sinceit uses the selfsame infrastructuresoftware for running apps on-premiseor in the cloud. Microsoftadditional provides WindowsAzure, its own PaaS offering.SPIDEROAKOne of themost securecloudproviders,SpiderOakenables usersto protecttheir datawithencryption,so as topreventunauthorizedaccess of thesame.SUGARSYNCAs the name suggests, SugarSync basicallyprovides file sync and file sharing services.This provider offers 5GB of free storage space.You can switch to a paid package if you needmore space.