Cloud computing allows companies to access applications and store data remotely via the internet instead of locally. It provides scalable IT resources on demand that can be accessed from anywhere. Some key benefits include reduced costs, increased flexibility and collaboration capabilities. However, security and privacy concerns remain top issues that need to be addressed. Control testing and governance models are important to effectively mitigate risks when using cloud services. Case studies of companies like Salesforce.com and GSK demonstrate how cloud can drive innovation while reducing IT costs through the subscription-based model.