Artificial Intelligence (AI) has evolved into one of the most transformative technological paradigms of the 21st century. From rule-based expert systems to deep neural architectures capable of generating human-like content, AI has reshaped industries, research methodologies, and socio-economic structures. This research paper provides a comprehensive IEEE-style analysis of Artificial Intelligence and its next frontier. The study explores historical evolution, mathematical foundations, neural architectures, optimization strategies, ethical challenges, security concerns, and future research directions including Artificial General Intelligence (AGI), Edge AI, Generative AI, and sustainable intelligent systems. The paper integrates theoretical modelling, system design frameworks, experimental simulation analysis, and performance evaluation metrics suitable for journal-level academic submission.