Operating income is that income which is earned through primary business activity while non operating income is that part of income which is not generated through primary operations of business like interest income, dividend income etc.

primary colors

primary election

primary source of income

primary residence or primary place of residence

primary function

primary caregiver

Selling his paintings.

the level of income

The average national income of the primary sector in India is $1,219 a year. By 2020, the amount is expected to rise to $4,200.