The Ngram Viewer will let you compare making use of multiple words or names in one graph. The example that I give up this video is to compare making use of the terms “National Parks,” “National Forests,” and “National Forest Service.” By taking a look at the Ngram Viewer for those terms I can see that they start to appear more often around 1890, have a lull in the 1940s and 1950s, and after that appear more frequently once again in the 1960s..
Ngram Viewer is based on books indexed in Google Books. That is why listed below every graph created by Ngram Viewer you will find a list of books about each of your search terms. Those books are arranged by date..
A 3rd element of Ngram Viewer to note is that it works with multiple languages consisting of English, French, Chinese, German, Italian, Russian, Hebrew, and Spanish..

Googles.
Ngram Viewer is a search tool that trainees can use to check out using words and names in books published between 1800 and 2019. The Ngram Viewer reveals users a chart showing the very first appearance of a word or name in literature and the frequency with which that word or name appears in literature since 1800. The graph is based upon the books and periodicals that are indexed in Google Books.

Ngram Viewer is a search tool that students can use to explore the use of words and names in books released in between 1800 and 2019. The Ngram Viewer shows users a chart illustrating the first look of a word or name in literature and the frequency with which that word or name appears in literature considering that 1800. The Ngram Viewer will let you compare the use of multiple words or names in one graph.

By the method, the book that I pointed out in the video is That Wild Country by Mark Kenyon..

Applications for Education.
As I pointed out in the video above, the Ngram Viewer can provide a good method to start a research activity for students. Have them go into a few words then analyze the chart to identify peaks and valleys in the frequency of the words use. Then ask them to attempt to identify what would have caused those words to be utilized more or less often at various durations in history.