The Object Definition Language (ODL) is an object modeling language defined by the Object Database Management Group
(ODMG). The task of the Object Definition Language is to describe the types of the database schema. The ODL modeling language defines keywords and attributes that identify the data type with a label. Such attributes can be the columns of a relational database, for example, an attribute can be the name or the date of birth, the place of residence or the preferred party. Relationships are established between attributes, for example, the relationship (Relationship) between age and party. In addition, the ODL language has further possibilities for nesting and defining data types.