An ERP would involve integrating all the systems together and having one database schema for everything. A Data Warehouse would involve creating a copy database (or copy databases) for analysis reasons. The Data Warehouse could extract information from the original repositories or the ERP system.
Enterprise resource planning (ERP) refers to a type of software that organizations use to manage day-to-day business activities such as accounting, procurement, project management, risk management and compliance, and supply chain operations