There are two versions of Azure DevOps: the cloud version and the on-premises version. We use the cloud version in very few situations, but most of our software is based on Azure DevOps on-premises.
We are a software house, and we develop software. We use it to store our source code; that is, it is the repository for our source code.
We have different teams working on different products, and each one uses a different methodology and a different process. Azure DevOps helps with that. For instance, one group may be using Scrum as a methodology to develop their software. The other group could also be using Scrum but with CDCI (continuous development, continuous integration), which helps a lot when you have to develop, test, and deploy the solution.