Which development model uses iterative processes to release well-tested code in smaller blocks, with development and provisioning tasks conceived as continuous?

The development model that employs iterative processes to release well-tested code in smaller increments, while embracing continuous development and provisioning tasks, is Agile. Agile methodologies prioritize adaptability, collaboration, and customer feedback, enabling teams to produce functional software more frequently and with a focus on quality.

In Agile, the development is divided into short cycles called iterations or sprints, during which features are developed, tested, and reviewed. This approach allows teams to incorporate changes based on stakeholder input rapidly, enhancing the final product's relevance and usability. The emphasis on continuous integration and continuous delivery ensures that code is continuously tested and improved upon, minimizing the risk of deployment failures.

This model contrasts with others such as the Waterfall approach, which follows a linear, sequential process, often making it more challenging to accommodate changes once development begins. While the Spiral model includes elements of iteration, it focuses more on risk management and requires a more structured approach to development phases. SecDevOps integrates security practices within the DevOps process, emphasizing the collaboration between development and operations teams, but doesn't specifically align with the iterative and incremental delivery focus attributed to Agile. Thus, Agile best fits the description of a model that utilizes iterative processes while delivering small, well-tested increments.