$(30$ points$)$ Please answer the following questions in a few sentences

$(1)(5$ points$)$ Why is a thread referred to as a lightweight process?

$(2)(5$ points$)$ Please describe data parallelism and task parallelism.

$(3)(5$ points$)$ Explain the concept of context switching and further explain why the overhead is more if switching to a thread belong to other processes?

$(4)(5$ points$)$ Please describe the pros and cons of one$-$to$-$one thread mapping scheme.

$(5)(5$ points$)$ Please describe the concept of CPU utilization, waiting time, turnaround time, response time and throughput.

$(6)(5$ points$)$ Please describe the advantages in MLFQ scheduling.