The way to think about ML.NET is really a higher level framework which comes built in with traditional ML trainers, transforms etc. and through its extensibility allows .NET developers to also use other leading frameworks for deep learning e.g. TensorFlow and standards e.g. ONNX models using one uniform set of APIs.

You can learn more about ML.NET here: https://dotnet.microsoft.com/apps/machinelearning-ai/ml-dotn...

No, cntk is focused on deep learning and ml.net is more focused on traditional ML as well as making it easier to deploy trained deep learning Tensorflow or ONNX models in your apps and services