Salesforce is the Customer Success Platform. Our social and mobile cloud technologies—including our flagship sales and CRM applications—help companies connect with customers, partners, and employees in entirely new ways.
Salesforce is originally a ‘Customer Relationship Management (CRM) software’. CRM is utilized for managing customer interaction such as scheduling tasks, emailing, texting, and many more. Salesforce grew into a cloud software solution and acquired several other companies for Paas and Saas.
Introducing Force.com : lForce.com is a cloud computing platform as a service system from Salesforce.com, used by developers to build multitenant applications hosted on their servers as a service. Salesforce.com is the Sales Cloud for ready-to-use products for CRM. lForce.com does not expose the underlying infrastructure.
Multi-tenancy: Multi-tenancy refers to a principle in software architecture where a single instance of the software runs on a server, serving multiple client- organizations (tenants). Multi-tenancy contrasts with multi-instance architectures where separate software instances (or hardware systems) operate on behalf of different client organizations.
Chatter is a brand-new way to collaborate at work. Because status information about people and important projects is automatically pushed to you, Chatter makes it easy to connect with the people and information you care about most.
Chatter Example: http://www.salesforce.com/chatter/gettingstarted/examples/sales
Salesforce: Salesforce is also 3-tier, but many of the internals are handled through abstraction. There are:
Out-of-box interfaces, which include security, dashboards, workflow, and user interfaces. Coding is optional.
VisualForce is an editor for customization of User Interfaces if not out-of-box.
Apex, using the developer console is for writing code to the Salesforce API, for example a SOAP or batch application for importing custom data.