DevOps in IT operations is best described as:

DevOps is best described as a combination of software development and IT operations because it embodies a set of practices that emphasizes collaboration, communication, and integration between these two traditionally separate fields. The core goal of DevOps is to shorten the development lifecycle, enhance deployment frequency, and provide a more stable operating environment. By merging the functions of development (Dev) and operations (Ops), teams can work together more efficiently, sharing responsibilities and combining workflows. This results in improved productivity and faster turnaround times for delivering software products and updates.

The other options highlight different concepts that do not align with the central tenets of DevOps. For example, while project management methodologies can guide how projects are executed, they do not inherently incorporate the operational and developmental integration that defines DevOps. Similarly, while IT security measures are crucial for securing applications and systems, they are not representative of the DevOps culture, which centers more on development and operations synergy rather than security practices alone. Finally, an approach to increase hardware efficiency does not capture the collaborative and iterative spirit that is fundamental to DevOps, which is primarily focused on enhancing software delivery and operational continuity.