I understand from your question that you asked for differences between software physical and logical specification (not physical and logical data models).
Let's dive into software physical and logical specification;
Refers to the hardware aspects of the system which includes how the software operates in a physical environment. For example, hardware requirements (processor, memory, storage), system config (os, network), and compatibility (supported hardware, third-party integrations).
For instance, a mobile app requires at least 4 GB RAM to run efficiently.
It refers to the abstract design aspects of the software, focusing on its functionality and behavior. For example, functional requirements (Features, expected behaviors), data model (database schema, attributes, relationships), process flows (user journeys, workflows).
For instance, a web app that processes customer orders and update inventory database