Multi-cloud computing, the utilization of multiple cloud computing services in a single heterogeneous architecture, has gained significant traction in recent years due to its potential for enhancing flexibility, resilience, and performance. This paper provides an overview of multi-cloud computing, exploring its key concepts, advantages, challenges, and best practices. It examines the motivations behind adopting multi-cloud strategies, the various deployment models, management approaches, and emerging trends. Additionally, the paper discusses the implications of multi-cloud computing for security, interoperability, and vendor lock-in. Through a comprehensive analysis, this paper aims to offer insights into the complexities and opportunities associated with multi-cloud environments.