What is the purpose of a conversion function?

A conversion function is specifically designed to change the data type of a given value from one type to another. This is fundamental in programming and data handling since different operations and functions require specific data types to process information correctly. For example, if you have a numerical value stored as a string and you need to perform mathematical operations, a conversion function will be used to convert that string to an integer or float type.

Manipulating data types is essential for ensuring that applications can handle and process data as expected, avoiding errors related to mismatched types during operations like calculations, comparisons, or data manipulation. The other options refer to different concepts, such as output formatting, validation, or performance optimization, but they do not focus on the primary function of type conversion itself. Thus, the answer accurately captures the main role of conversion functions within programming contexts.