In this article, we are going to use the following table for some examples:-

CREATE TABLE [dbo]. [Employee](
[Empid] [Int] IDENTITY (1, 1) NOT NULL Primary key,
[EmpNumber] [nvarchar](50) NOT NULL,
[EmpFirstName] [nvarchar](150) NOT NULL,
[EmpLAStName] [nvarchar](150) NULL,
[EmpEmail] [nvarchar](150) NULL,
[Salary] [int] NULL
)

We insert following data into the above tables:-

Insert Into Employee (EmpNumber,EmpFirstName,EmpLAStName,EmpEmail,salary)
Values('A001','Vivek','Johari','samir@abcmail.com',200000)

Insert Into Employee (EmpNumber,EmpFirstName,EmpLAStName,EmpEmail,salary)
Values('A002','Amit','Kumar','amit@abcmail.com',100000)

Insert Into Employee (EmpNumber,EmpFirstName,EmpLAStName,EmpEmail,salary)
Values('A003','Neha','Sharma','neha@abcmail.com',300000)

Insert Into Employee (EmpNumber,EmpFirstName,EmpLAStName,EmpEmail,salary)
Values('A004','Chandra','Singh','vivek@abcmail.com',320000)

Insert Into Employee (EmpNumber,EmpFirstName,EmpLAStName,EmpEmail,salary)
Values('A005','Avinash', 'Dubey','avinash@abcmail.com',250000)
 
For example,

      Select AVG(salary) from employee

will give the given result:-

234000