Relational Model: -
The relational database organizes data in tables. Each table is identified by a unique table name, and is organized by rows and columns. Each column within a table also has a unique name. Columns store the values for a specific attribute, e.g. cover group, tree height.A relational database usually contains three types 0f relationship between tables. Usually here two types of table are defined- the source table & the destination table. If the purpose is to add attribute data from a table to the feature attribute table, then the feature attribute table is the destination table and the other one is the source table. Owing ot this manner, three types of relationships can be created.
One-to-one Relationship- Here one and only one record in the destination table is related to one and only one record in the source table.
One-to-Many Relationship- This means that one record in the destination table may be related to more than one record in the source table.
Many-to-One Relationship- This type of relationship is just opposite to the One-to-Many Relationship. Here two or more records in the destination table may be related to one record in the source table.