What is a class in Salesforce?

C.

In the context of programming, a class is a blueprint or a template that defines the properties and behavior of an object. It serves as a container for variables and functions that are related to a specific entity.

In Apex, which is a programming language used to develop Salesforce applications, a class is a fundamental building block that allows developers to create custom business logic and manipulate data. A class can be used to define custom objects, controllers, triggers, and other types of logic.

Visualforce, on the other hand, is a framework used to build user interfaces in Salesforce. In Visualforce, a class can be used as a controller to define the behavior of a custom page. The controller class can contain variables, functions, and other logic that can be used to manipulate data and interact with the user interface.

APIs (Application Programming Interfaces) are a set of protocols and tools used to build software applications. In Salesforce, APIs can be used to integrate external systems with Salesforce or to build custom applications that interact with Salesforce data.

Therefore, answer A is incorrect because it combines Apex, Visualforce, and APIs into one category, which are all different concepts with different uses.

Answer B is incorrect because a database class method is a specific method that can be used in Apex to interact with the database, but it does not define what a class is.

Answer C is partially correct because a class can be used as a template to create objects, but it does not define what a class is or its purpose.

Answer D is incorrect because Ajax toolkit is a set of libraries used to develop web applications, and it is not related to the concept of a class in Apex or Visualforce.