Abstract:This survey offers a comprehensive review of recent advancements in multimodal alignment and fusion within machine learning, spurred by the growing diversity of data types such as text, images, audio, and video. Multimodal integration enables improved model accuracy and broader applicability by leveraging complementary information across different modalities, as well as facilitating knowledge transfer in situations with limited data. We systematically categorize and analyze existing alignment and fusion techniques, drawing insights from an extensive review of more than 200 relevant papers. Furthermore, this survey addresses the challenges of multimodal data integration - including alignment issues, noise resilience, and disparities in feature representation - while focusing on applications in domains like social media analysis, medical imaging, and emotion recognition. The insights provided are intended to guide future research towards optimizing multimodal learning systems to enhance their scalability, robustness, and generalizability across various applications.