What is an independent contractor and does an employer have the right to control the mode and manner of the work?

"An independent contractor is one who, in rendering services, exercises an independent employment, and represents the employer only as to the results of his work and not as to the means whereby it is to be accomplished." (George v. Chaplin (1929) 99 Cal.App. 709, 712 [where there was evidence that the employer, a car dealership, had the right to control the mode and manner of the work done by an automobile salesman when he injured customers in a car demonstration, meaning the salesman was not an independent contractor].)