Visualforce is very interesting framework in Salesforce. It is a markup language you can use this to develop user interface according to your requirements in Salesforce. Visualforce runs on Force.com platform

To create and view Visualforce page in Salesforce, check the below link

https://www.infallibletechie.com/2014/08/how-to-create-and-view-visualforce-page.html

Cheers!!!