To customize the user interface salesforce has a number of ways.
- Point and click : Using drag-and-drop tools and simple point-and-click the Salesforce web and mobile interfaces are highly customizable
- Lightning : Salesforce's new Lightning technology includes Lightning Components, Lightning App Builder, Lightning Experience, and Lightning Design System.
- SalesForce provides two ways to build user interfaces. These are Page Builder and VisualForce. PageBuilder automatically generates pages with default look-and-feel. VisualForce allows developers to define their own user interface.
- VisualForce plays the role of JSP or ASP in SalesForce. It is used to develop user interface for SalesForce applications.
- VisualForce can be used to support other devices like phones, PDAs.
- apex:form is used to display a form. Other VisualForce display elements like text box, checkbox are included in a form.
For more info Visualforce
- Lightning includes the Lightning Component Framework. Through the Lightning Component makes it easy to develop application.
- Components are the self-contained and reusable units of an app.
- The Developer Console provides tools for developing your components and applications.
- Aura framework is a open source for building the Lightning Component framework
For more info trailhead.salesforce.com