What do you mean by the term frictional unemployment?

Frictional unemployment arises due to when people are looking to change or shift their jobs. When people are looking for a new job leaving their old job vacant. That part of the jobless total caused by people simply changing jobs and taking their time about it, because they are spending time on job search or are taking a break before starting with a new employer. There is likely to be some frictional unemployment even when there is technically full employment, because most people change jobs from time to time.