A value converter acts as a bridge between a target and a source and it is necessary when a target is bound with one source, for instance you have a text box and a button control. You want to enable or disable the button control when the text of the text box is filled or null. In this case you need to convert the string data to Boolean. This is possible using a Value Converter. To implement Value Converters, there is the requirement to inherit from I Value Converter in the System.Windows.Data namespace and implement the two methods Convert and Convert Back.