Answer:
Visual force
Step-by-step explanation:
Visual force is a programming language made and designed for the purpose of sales force, which shall allow the company to create and expand its horizons. It helps to create a user interface.
With the help of that user interface the company can interact with as many number of people as they want. Also it uses the defined database, that you would create with the help of such interface.
Visual force can be designed in the manner as required by the company. Simple or complex depending upon the use as required.