Azure DevOps has a feature where it can connect with external tools via service connection which allows easily integrate multiple tools required for your project development and deployment purposes. However, when you have multiple Azure DevOps team projects and dedicated service connection for each project, it is not easy to manage service connections. As a solution for this, Azure DevOps has introduced secured and shared service connection between projects. As example, if the team has one azure subscription for development purposes, they can connect with azure using one shared service connection between Azure DevOps projects.
You can find this feature in Azure DevOps settings section. Go to Azure DevOps settings and select service connections under pipeline section. You can add new service connection or edit existing connection from this page. We use existing service connection to explain the feature in this blog post. Go to security section of the selected service connection.