Definition - What does Multi-Cloud Deployment mean?
A multi-cloud deployment is, as the name suggests, the use of two or more cloud computing systems at the same time. The deployment might use public clouds, private clouds or some combination of the two. Multi-cloud deployments aim to offer redundancy in case of hardware/software failures and and avoid vendor lock-in.
Techopedia explains Multi-Cloud Deployment
With a multi-cloud deployment, businesses can use two or more cloud computing platforms at the same time. There are various reasons why they might want to do this. One team might be using Microsoft products and Microsoft's Azure platform would be a natural, while at the same time another team prefers Amazon Web Services. A company might also want a private cloud for handling confidential data while using a public cloud for a web app. Companies may also want to fail over to another cloud in case of problems with their primary cloud platform.
There are a number of third-party software tools for managing multiple cloud deployments.