This is "generic the" see https://ell.stackexchange.com/questions/34623/the-generic-use-of-the and probably other questions/answers.
– James KNov 06 '23 at 22:11
Also https://ell.stackexchange.com/questions/22647/uses-of-the-definite-article-the-in-generic-noun-phrases?rq=1
– James KNov 06 '23 at 22:11
and https://ell.stackexchange.com/questions/84763/the-elephant-and-elephant-proper-and-common-noun?noredirect=1&lq=1
– James KNov 06 '23 at 22:11
You should give a proper reference to the book (author, title, date, page, etc), not just post an image. But this looks like a duplicate.
– Stuart FNov 07 '23 at 15:48
The book's name is High school English Grammar & Composition written by Wren & Martin first heading The Sentence
– Ranwinsu NillNov 07 '23 at 16:23