A function is a standalone block of code, whereas a method is associated with an object and can access that object’s data.

In programming, both functions and methods are reusable blocks of code designed to execute specific tasks. However, they are utilized in different contexts and have varying access to data. A function operates independently; it can take inputs, perform computations, and return outputs. Functions are typically defined outside of classes in procedural programming languages such as C, allowing them to be called independently. They also play a central role in functional programming languages like Haskell, where they are the primary means of structuring and building software.

In contrast, a method is a function that is linked to an object in object-oriented programming (OOP). Methods are defined within classes and are specifically designed to manipulate the data contained within the objects they belong to. Unlike standalone functions, methods can access and modify the data members of their respective classes. This capability is essential in OOP languages such as Java, Python, and C++.

The fundamental distinction between a function and a method lies in the concept of ‘state’. A function does not maintain any state; it operates solely on the inputs it receives and does not retain information between calls. In contrast, a method can have a state because it is associated with an object, allowing it to access and modify that object’s data. Consequently, the behavior of a method can vary depending on the state of the object to which it belongs.

In summary, while both functions and methods perform computations, they serve different purposes in distinct programming paradigms and have different levels of data access. Functions are standalone entities used in procedural and functional programming, whereas methods are associated with objects and employed in object-oriented programming.