What does it mean to start a business out of necessity?

There are two ways to look at this question.

One way is to say that a person started a business because he couldn't find a job or he was retrenched, so he starts a business primarily with the intention of paying bills and meeting his needs. His temperament may or may not be suited for entrepreneurship. He might just get into a job as soon as he gets the opportunity to so. Such entrepreneurs are known as "necessity entrepreneurs".

The second way is that a person started a business because the product s/he deals is on its way to become a necessity in people's lives. So, the entrepreneur sees an opportunity to start a business and earn profits. Such entrepreneurs are known as "opportunity entrepreneurs." Opportunity entrepreneurs have what it takes to stick with the ups and downs of setting up a new business and turn it into a success.