Agility in software development is the disciplined ability to adapt, learn, and deliver value under changing conditions. It should not be a casual form of flexibility but rather focus on engineered responsiveness rooted in continuous feedback, collaboration, and iteration. Modern software systems rarely exist in isolation; they are part of intricate, interdependent ecosystems that evolve as quickly as the technologies that sustain them. In this environment, requirements are fluid, customer feedback drives innovation, and new vulnerabilities or opportunities emerge unexpectedly. Agility provides the structure and mindset required to navigate this constant state of change without sacrificing quality or control.