Final answer:
Outsourcing refers to the practice of a company hiring an external vendor to perform tasks which were previously done internally, often leading to cost savings and job market polarization.
Step-by-step explanation:
Hiring an external vendor for a task rather than doing it internally is called outsourcing. This practice refers to a company contracting with an outside organization to perform services or create goods that were traditionally performed in-house by the company's own employees and staff. Outsourcing can be done within the country where the company is located or involve international entities, sometimes leading to offshoring, where the outsourced operations are moved to another country to take advantage of lower labor costs. While outsourcing can lead to cost savings on labor and increase efficiency, it has also contributed to the polarization of the job market and the rise of structural unemployment, as more low-end and high-end jobs become available, with declining opportunities for mid-level jobs.