1. Database ModelsThe initial development of data storage began with the file system, and these files actually have no relationship or information of the application that uses them. These files are accessed through the application containing the information or file name, therefore these files cannot be considered databases but used to store database information. The application software is not aware of the file structure but compared to it, the database management system consists of metadata and it is the responsibility of the metadata to translate the files in the physical layer as well as create the logical layer. Conceptually metadata is the data stored in the database catalog, how the data is stored in the database, and how the relationship between the data would develop. The example of flat file system is just like an application that manages customer records via cutomer_data.txt.1.1 Hierarchical Database Management System In hierarchical modeling technique the database is slightly revolutionized and organized and the schema is just like the record file indicating the address of certain data or indicating the place of actual recording. The following example shows that two pointers clearly point to the web page and the street address, but for the address or URL of the pointer you might take from the record one step above the actual information or data. Figure 7. Hierarchical Model The relationship in this case is parent child with one parent and many children.1.2 Network Database Management SystemThe network database model is somewhat similar to the hierarchical data model but this model is developed to first time from CODASYL network although initial network database was Honeywell IDS but it was not stand.... ..half of the document......I am developing this database as everything works logically and any fact that is part of the real world but is not present in the database, it never exists for the database. Deductive database claims to adopt several properties of relational database and declarative property is one such property. The declarative property is about querying or updating information based on requirements without knowing anything about how it works. There are two important variations in deductive database system and these are as follows: Expert database system Knowledge based database system In pure deductive system data could be present in both primary and secondary section of memory but in both types of data above should be present in the primary section. The programming languages ​​used to implement the deductive system are known as Prolog and Data log.