String conversion is the process of changing data from one format to a string, which is a sequence of characters. This is important in programming because many functions and operations require data to be in string format. For example, when you want to display a number or combine different types of data, you often need to convert them into strings first. In many programming languages, such as Python or Java, there are built-in functions to help with string conversion. These functions can take numbers, lists, or even objects and turn them into strings, making it easier to manipulate and display data in a user-friendly way.