Which is the better in SAP MM and SAP PI ? I know SAP MM

On the other hand, SAP PI, now known as SAP Process Orchestration (PO), is an integration platform that enables the seamless integration of different systems and applications within an organization.

SAP MM (Material Management) and SAP PI (Process Integration) are two different modules within the SAP ecosystem, serving different purposes. SAP MM is focused on managing procurement processes, inventory management, and material valuation. On the other hand, SAP PI, now known as SAP Process Orchestration (PO), is an integration platform that enables the seamless integration of different systems and applications within an organization.

Comparing the two is not straightforward as they serve different functions. If you are familiar with SAP MM and are looking to enhance integration capabilities within your organization, then SAP PI/PO might be a suitable choice. However, the decision of which module is "better" depends on the specific needs and goals of your organization.