What term describes a person who sells their work or services by the job rather than receiving a regular salary?

The term that best describes a person who sells their work or services by the job, rather than receiving a regular salary, is "Freelance contractor." Freelancers are typically self-employed individuals who take on various projects or jobs for different clients, often working on a short-term or contractual basis. This allows for flexibility in choosing which projects to undertake and the ability to work for multiple clients simultaneously.

In contrast, a permanent employee would typically have a steady role within a specific company, receiving a regular paycheck and benefits. An intern usually works for a limited time often as part of their education, gaining experience rather than operating as a service provider for hire. Part-time workers have a consistent arrangement with an employer but may work fewer hours than full-time employees, which doesn't align with the concept of selling services by the job.