Asanka Padmakumara takes a look at the user defined managed identity:
If you are familiar with Managed Identity concepts in ADF, each ADF instance comes with own System Assigned Managed Identity (MI). We can use that MI to control ADF’s access to any data sources which support Azure AD based authentication. This is considered to be the most secured and recommended way of authenticating ADF with cloud systems. If not, you can use Azure Key vault to store credentials. Let’s take an example on to discuss how User Assigned Managed Identity helps for manage access within multiple ADF environment.
Click through to see how the user assigned managed identity makes life better.