This book unveils the details of the OSI model's seven layers—Physical, Data Link, Network, Transport, Session, Presentation, and Application—using the 5W1H model to explore the 'what,' 'why,' 'who,' 'when,' 'which,' and 'how' of each layer. Whether you're just starting out or a seasoned pro seeking insights, this book is your go-to guide. Dive into the 'how' of data transmission, uncover the 'why' behind each layer's importance, and grasp the basic principles that make modern communication systems work. Whether you're cruising through the layers for the first time or refreshing your knowledge, let this book be your key to unlocking the mysteries of the OSI model, bringing clarity and depth to your understanding of network architecture.