Java 21 vs Java 17 vs Java 8 Implementation Java has offered powerful features with each new version significantly over the years, that enhance developer productivity, code readability, and performance. In this analysis based article, we will explore the Hotel Room Booking System implemented in Java 8, Java 17, and Java 21, and compare how modern Java features simplify development while maintaining backward compatibility. This comparison should also helpful as a practical guide for developers considering migration or simply wanting to leverage modern Java effectively. The Hotel Booking System is a real-world use case that involves Dynamic pricing (room types, discounts), Business rules (membership benefits, seasonal offers) & Concurrency (parallel processing for bulk bookings). In this implementation we will Compare coding styles – from verbose Java 8 to concise