Database architecture refers to the design of the database system, how data is stored, how relationships are defined, and how data is accessed.

Tables, Rows, and Columns

1. Tables

• A table is a collection of data organized into rows and columns.
• Each table represents an entity, such as employees, orders, or products.
• Tables are defined by a schema that specifies their columns (attributes) and the data types of those columns.

Example: A table called employees might have columns such as employee_id, first_name, last_name, hire_date, salary.

2. Rows (Records)

• A row in a table represents a single record or instance of the entity.
• For example, in the employees table, each row would represent an individual employee, with specific values for each column.

Example:

3. Columns (Attributes)

• Columns define the types of data that each record can store, such as name, address, phone_number, etc.
• Each column has a name and a data type (e.g., VARCHAR for text, INT for integers, DATE for dates).

Example (for employees table):

• employee_id (INT)
• first_name (VARCHAR)
• last_name (VARCHAR)
• hire_date (DATE)
• salary (DECIMAL)