Successfactors is presently leading the SAP cloud system. It mainly works on Human capital management (HCM) solutions which focus on HR cloud system includes recruiting the employees, employee performance management, tracking software etc.. SAP SucessFactors is a cloud(over internet and needn't download any application) based HRM(Human Resources - People in your Company) Solution which can be accessed everywhere through Mobile, Desktop and Tablets.
We are moving from individual Server Business Model to cloud based Business Model. I suppose you know the benefits of Cloud based Models, in case you haven't let me brief Cloud offers benefits like
1. Anywhere and Everywhere - you could access your applcations anywhere, everywhere and on any device, only if you are connected through Internet.
2. Reliable and Safety - In old days when a server crashes, the application went offline for that time it takes it to fix it. Through cloud solutions, the data resides on many servers, so when one server goes down, other server offers you the services. And also the data recovery, you could retrieve the data from the other services.
3. Flexibilty - based on the number of users accessing your service, the bandwidth capacity of cloud services can ne increased, so there would no inconvenience to the users and vice versa.
4. Cost Effective - Small business can thrive using cloud services, for you needn't buy any hardware. It's would be a subscription based model, so you but more services as your business grows. The best example is AWS(Amazon Web Services). You could be more competitve.