Explicit casting is a programming technique used to convert a variable from one data type to another. This is done by specifying the desired type in the code, allowing the programmer to control how the conversion occurs. For example, converting an integer to a floating-point number can be done using explicit casting to ensure the value is treated as a decimal. In many programming languages, explicit casting is necessary when the conversion might lead to data loss or when the types are not automatically compatible. This helps prevent errors and ensures that the program behaves as expected, especially when dealing with different types of data, such as integers and floats.