New keywords are keywords that appear in the last month of the date range filter, but not in the previous month (i.e. May-July would compare July's keyword list to June's to determine new keywords).
Trending keywords are keywords representing a significant rise in traffic to the site compared to previous months. This includes all keywords with 50%+ change and keywords with a large change in volume.
Utilize these filters to understand new search terms, products, or ways of searching within an Industry or Competitive Set. Identify the terms that were not used in prior months or were receiving significantly less traffic in the prior month.