Derivation is the process of obtaining a new word or form from an existing word, often by adding prefixes or suffixes. For example, the word happy can be transformed into happiness by adding the suffix "-ness." This process helps expand the vocabulary and allows for more precise expression in language. In mathematics, derivation refers to the process of finding the derivative of a function. The derivative measures how a function changes as its input changes, providing insights into its behavior. For instance, the derivative of the function f(x) = x^2 is f'(x) = 2x, indicating the rate of change of the function at any point.