An independent contractor is a person who an employer hires to complete a project. The employer does not have control over how the project is completed. In California, a person hired to do something for the benefit of another is assumed to be an employee unless the employer proves otherwise. See, Labor Code, § 3357.
For example, if a small donut shop hires a web designer to build a website for the business and agrees to pay a set amount for the project, then the web designer is an independent contractor and not an employee.