This document describes an online hotel management system project. The proposed system allows customers to reserve hotel rooms online by checking availability and registering on the system. It also allows administrators to view reservation details and daily income. The existing manual system is time-consuming and prone to errors. The online system aims to save time for customers and provide secure booking from anywhere on the internet. It uses PHP for development, MySQL for the database, and XAMPP as the web server on Windows or Linux. UML diagrams are included, such as use case, sequence, activity, and class diagrams to model the user and administrator modules.