Docker, an open-source system of software containers, revolutionizes cloud computing by providing a lightweight, portable, and scalable environment for running applications across various platforms without the need for virtual machines. Originating from a proprietary project by Solomon Hykes at dotCloud, Docker became open source in 2013 and quickly gained popularity due to its ability to virtualize an operating system alongside applications and components within isolated containers. This technology enhances efficiency and scalability by sharing operating systems, reducing the load on system resources, and allowing rapid deployment. Despite Docker's advantages, it presents some challenges, such as a steep learning curve and security concerns compared to virtual machines. The rise of Docker also aligns with the broader shift towards microservices, which promote modular, collaborative development processes. While Docker is not a one-size-fits-all solution, its integration into cloud architecture represents a significant evolution in computing, supported by substantial investments and increasing adoption across the industry.