Final answer:
The traditional meaning of a job as a set of well-defined responsibilities is changing due to various factors such as increased education and training requirements, greater diversity in the workforce, and the prevalence of multiple jobs throughout one's career.
Step-by-step explanation:
The traditional meaning of a job as a set of well-defined responsibilities is changing due to several factors. Firstly, the modern job market requires more education and training than ever before. Additionally, there is a greater representation of women and minority groups in the workforce. Furthermore, the concept of lifelong employment in the same job is no longer common, as individuals today can expect to hold multiple jobs throughout their careers.