With the continuous development of Industry 4.0 and the "Industrial Internet", the Industrial Internet of Things (IIoT), as the core of digital transformation, is becoming a vital part of the industrial sector. This article elaborates on the key technologies and typical characteristics of IIoT, offering readers solid knowledge to better understand its development and applications.

IIoT continuously integrates various acquisition and control sensors and controllers — endowed with sensing and monitoring capabilities — together with mobile communication and intelligent analysis technologies, into every link of the industrial production process. This significantly raises manufacturing efficiency, improves product quality, and reduces product cost and resource consumption, ultimately elevating traditional industry to a new intelligent stage. In application form, IIoT features real-time performance, automation, embedded software, security, and information interoperability.

• Comprehensive sensing: modern information collection and acquisition technologies obtain real-time status of industrial resources.

• Information transmission: reliable information exchange and sharing through various communication networks and the Internet.

• Intelligent processing: massive data is analyzed to enable intelligent decision-making and control.

• Information feedback: processed information is delivered as program instructions to each production link, optimizing production structure and plans.

• Intelligent sensing: sensors obtain various status information of industrial resources.

• Ubiquitous connectivity: wired or wireless means interconnect industrial resources.

• Digital modeling: industrial resources are mapped into digital space for abstract modeling and decision support.

• Real-time analysis: sensed data is processed and responded to in real time.

• Precision control: decisions made in the virtual space achieve precise control of resources.

• Iterative optimization: continuous learning and optimization reach optimal goals.

• IoT security: the security and reliability of the IIoT system are safeguarded.

• Sensing and control stage: intelligent sensing at the IoT edge.

• Interconnection stage: secure and efficient integration of heterogeneous networks.

• Data application stage: in-depth applications via data analytics and cloud computing.

• Innovative service model stage: customized, value-added, and O&M service models across fields.

As a vital part of industry, IIoT enables intelligent, efficient, and refined management of industrial resources through its key technologies. As IIoT evolves, we must prioritize IoT security and foster a sound environment for its application. The rise of IIoT brings unprecedented opportunities to industrial manufacturing and lays a solid foundation for an intelligent future.