Cloud migration refers to the process of moving digital assets like data, applications, and workloads from one cloud service provider (e.g., AWS, Azure, Google Cloud) to another. It differs from migrating to the cloud from on-premises, as it involves transferring resources already operating in a cloud environment. This requires careful planning to handle differences in underlying platforms, services, APIs, and management tools between the source and target clouds.

Common real-world examples include businesses shifting workloads to reduce costs with a different provider's pricing model, or adopting a multi-cloud strategy by moving specific applications. Industries like e-commerce or finance frequently undertake this. Tools such as Azure Migrate, AWS Application Migration Service, and Google Cloud Migrate assist by automating aspects like virtual machine (VM) replication. Applications might be migrated "lift-and-shift" (moving VMs as-is), or refactored to use equivalent services like managed databases.

Successfully migrating offers flexibility and potential cost savings but poses challenges. Limitations include complexity, potential downtime, data transfer fees, configuration compatibility issues, and skill gaps. It mitigates vendor lock-in risks, an ethical and strategic consideration. While achievable, especially with hybrid strategies initially, thorough assessment and execution planning are vital due to the risks involved. Multi-cloud tools and standards are simplifying future migrations.