The commencement of the sixth-generation (6G) wireless networks represents a fundamental shift in the integration of communication and sensing technologies to support next-generation applications. Integrated sensing and communication (ISAC) is a key concept in this evolution, enabling end-to-end support for both communication and sensing within a unified framework. It enhances spectrum efficiency, reduces latency, and supports diverse use cases, including smart cities, autonomous systems, and perceptive environments. This tutorial provides a comprehensive overview of ISAC's role in 6G networks, beginning with its evolution since 5G and the technical drivers behind its adoption. Core principles and system variations of ISAC are introduced, followed by an in-depth discussion of the enabling technologies that facilitate its practical deployment. The paper further analyzes current research directions to highlight key challenges, open issues, and emerging trends. Design insights and recommendations are also presented to support future development and implementation. This work ultimately tries to address three central questions: Why is ISAC essential for 6G? What innovations does it bring? How will it shape the future of wireless communication?

翻译：第六代（6G）无线网络的启动，代表了通信与感知技术融合以支撑下一代应用的基础性变革。集成感知与通信（ISAC）是这一演进中的关键概念，它在统一框架内实现对通信和感知的端到端支持。它提升了频谱效率、降低了延迟，并支持多样化的应用场景，包括智慧城市、自主系统和感知环境。本教程全面概述了ISAC在6G网络中的作用，从自5G以来的演进历程及其被采用的技术驱动因素入手展开。介绍了ISAC的核心原理和系统变体，随后深入讨论了促进其实际部署的关键使能技术。本文进一步分析了当前的研究方向，以突出关键挑战、开放问题和新兴趋势。同时提出了设计见解和建议，以支持未来的开发与实施。本工作最终旨在解决三个核心问题：为何ISAC对6G至关重要？它带来了哪些创新？它将如何塑造无线通信的未来？