Declarative development in Salesforce.

Declarative development in Salesforce is done by point-and-click with out using single line of code using browser. In this method, Salesforce follows MVC Architecture when developing application.

ModelViewController
ObjectsApplicationsWorkflow Rules
FieldsTabsValidation Rules
RelationshipsPage LayoutsAssignment Rule
Records Types

Programmatic development in Salesforce.

In this model of development in Salesforce, Salesforce coding is required. The Salesforce MVC architecture are as follows.

ModelViewController
Web Services APIVisualforce PagesApex Controllers
Metadata APIVisualforce ComponentsApex Trigger
External ObjectSiteWeb Service API