The Network model replaces the hierarchical tree with a graph thus allowing more general connections among the nodes. The main difference of the network model from the hierarchical model, is its ability to handle many to many (N:N) relations. In other words, it allows a record to have more than one parent. Suppose an employee works for two departments. The strict hierarchical arrangement is not possible here and the tree becomes a more generalized graph - a network. The network model was evolved to specifically handle non-hierarchical relationships. As shown below data can belong to more than one parent. Note that there are lateral connections as well as top-down connections. A network structure thus allows 1:1 (one: one), l: M (one: many), M: M (many: many) relationships among entities.
In network database terminology, a relationship is a set. Each set is made up of at least two types of records: an owner record (equivalent to parent in the hierarchical model) and a member record (similar to the child record in the hierarchical model).
The database of Customer-Loan, which we discussed earlier for hierarchical model, is now represented for Network model as shown.
In can easily depict that now the information about the joint loan L1 appears single time, but in case of hierarchical model it appears for two times. Thus, it reduces the redundancy and is better as compared to hierarchical model.