ODI Model stores the metadata about the source and target tables.
A ODI model is a set of ODI datastore (table). A model can contain all tables from a database schema, or a subset of the tables from the schema. ODI does not call the tables “tables”, but call them datastore since they may not come from database. XML files, LDAP Tree, flat files, etc, are also datastores.
Unlike Informatica, which requires you to know whether a database table is a source or a target during the time when you importing the database table definition, ODI lets you to keep the model definition independently from the usage of the model.
The data warehouse staging tables are the source of the target tables and are the target of the OLTP tables. You have to import them and copy them when you do ETL development using Informatica.
ODI allows you to groups datastores into model folders and sub models.