The VIN decoder application is a web-based application built using Flask, a Python microframework, to connect with the RapidAPI VIN-decoder API. The application allows users to input a vehicle identification number (VIN) or plate number and state to retrieve information about the vehicle's history, specifications, and other relevant data. The application features dynamic switching of forms and corresponding resources based on user choice, with validation and error handling implemented using JavaScript and jQuery. The application also displays data in a user-friendly format, including lists and detailed information.