Defining Primary key and Foreign key On Tables

Primary and Foreign keyword is used to create Primary key and Foreign key on columns.
Create Parent Table

CREATE TABLE Department 
(
 Dept_ID int PRIMARY KEY, --Define primary key
 Name varchar (50) NOT NULL,
 Address varchar(100) NULL 
)
Go 

Create Child Table

CREATE TABLE Employee_Master 
(
 Employee_Id int PRIMARY KEY, --Define primary key
 Employee_Name varchar (50) NOT NULL,
 Pan_No varchar(10) NULL,
 --Define foreign key
 Dept_ID int FOREIGN KEY REFERENCES Department(Dept_ID)
)