Multi-cloud security is the practice of securing applications, data, and infrastructure across multiple cloud environments. Implementing a comprehensive security framework requires considering identity and access management, data security, network security, compliance, incident response, and cloud provider security. To avoid vendor lock-in and ensure flexibility, companies use a multi-cloud approach to leverage different cloud providers' strengths while mitigating their weaknesses. This approach offers benefits such as increased redundancy and resilience, improved performance and scalability, cost savings, and optimized cloud spending. However, it requires additional management and monitoring to ensure effective workload distribution and data security. Organizations must address unique security challenges, including data breaches, compliance challenges, cloud misconfigurations, lack of visibility, shadow IT, and vendor lock-in, by implementing a comprehensive multi-cloud security strategy that combines security best practices, risk assessments, and security tools and technologies.