Logical database modeling is required for compiling business requirements and representing the requirements as a model. It is mainly associated with the gathering of business needs rather than the database design.
Physical database modeling deals with designing the actual database based on the requirements gathered during logical database modeling. All the information gathered is converted into relational models and business models. During physical modeling, objects are defined at a level called a schema level. A schema is considered a group of objects which are related to each other in a database.