Final answer:
A class is a programming language construct that encapsulates variables, access procedures, and initialization code within an abstract data type.
Step-by-step explanation:
A class in programming encompasses variables, access procedures, and initialization code, encapsulating them into an abstract data type. In object-oriented programming, a class serves as a blueprint for creating objects. It defines the properties (variables) and behaviors (methods) that objects of that class can have.
For example, consider a class called 'Car'. This class can have variables like 'color', 'model', and 'year'. It can also have methods like 'start()', 'accelerate()', and 'stop()'. Objects of the 'Car' class can be created with different property values and can perform the defined behaviors.
In languages like Java, C++, and Python, classes are an essential part of the syntax and are used extensively for organizing code and implementing object-oriented principles.