RDBMS stands for relational database management system. A relational model can be represented as a table of rows and columns. A relational database has following major components:
1. Table
2. Record or Tuple
3. Field or Column name or Attribute
4. Domain
5. Instance
6. Schema
7. Keys
1. Table
A table is a collection of data represented in rows and columns. Each table has a name in database. For example, the following table “STUDENT” stores the information of students in database.
Table: STUDENT
| Student_Id | Student_Name | Student_Addr | Student_Age |
| 101 | Chaitanya | Dayal Bagh, Agra | 27 |
| 102 | Ajeet | Delhi | 26 |
| 103 | Rahul | Gurgaon | 24 |
| 104 | Shubham | Chennai | 25 |
2. Record or Tuple
Each row of a table is known as record. It is also known as tuple. For example, the following row is a record that we have taken from the above table.
| 102 | Ajeet | Delhi | 26 |
3. Field or Column name or Attribute
The above table “STUDENT” has four fields (or attributes): Student_Id, Student_Name, Student_Addr & Student_Age.
4. Domain
A domain is a set of permitted values for an attribute in table. For example, a domain of month-of-year can accept January, February,…December as values, a domain of dates can accept all possible valid dates etc. We specify domain of attribute while creating a table.
An attribute cannot accept values that are outside of their domains. For example, In the above table “STUDENT”, the Student_Id field has integer domain so that field cannot accept values that are not integers for example, Student_Id cannot has values like, “First”, 10.11 etc.
5. Instance and Schema
I have already covered instance and schema in a separate guide, you can refer the guide here.
6. Keys
This is our next topic, I have covered the keys in detail in separate tutorials. You can refer the keys index here.