The relational model is the most widely used of the three database structures. Most microcomputers use it so it is very common. It is used by most midrange and mainframe systems. The data elements within the database are viewed and stored in the form of simple two-dimensional tables which are referred to as relations. The table files are flat files which consist of rows and columns. Each row represents a single record in the file and the column represents a field.
The database can specify data attributes for multiple files at the same time and can relate the various data elements in one file to those in one or more other files. This cannot be done by flat files. Database management can show relations between two completely elements from various tables. Relational database can compare any file that has common data elements or fields. Information can be created from files in multiple physical locations. Three basic operations can be performed on a