Explanation:
Box 1: Dataset
Datasets must be created from paths in Azure datastores or public web URLs, for the data to be accessible by Azure Machine Learning.
Box 2: Linked service
Linked services are much like connection strings, which define the connection information needed for Data Factory to connect to external resources.
Box 3: Pipeline
A pipeline is a logical grouping of activities that together perform a task.
Reference:
https://k21academy.com/microsoft-azure/dp-100/datastores-and-datasets-in-azure/
https://docs.microsoft.com/en-us/azure/data-factory/concepts-linked-services
https://docs.microsoft.com/en-us/azure/data-factory/concepts-pipelines-activities