Annotation refers to the words that explain sentences, and also refers to the words that explain sentences. Can be in the form of text symbols, pictures, etc. Annotations are words that introduce and comment on the vocabulary, content, background and quotations of books or articles. The annotation of ancient books began in the pre-Qin period.
China in ancient times was divided into four parts, namely, annotation, explanation, biography, writing, sparseness, chapters and sentences. It contains a wide range of contents. Sound and meaning, time and place, people's deeds, allusions and background of the times are all annotation objects. There are footnotes, notes at the end of the text, and notes in brackets.
The text lists the notes of ancient books, with double-line notes and annotations. The notes of modern books are listed at the bottom of the main page of the text, called footnotes, also called personal letters. Those listed at the back of the article or book are called the last note. No matter which method is adopted, the arrangement of notes in the whole book generally requires unity to facilitate readers' reference. Annotations are widely used in teaching materials and are an important condition for students to learn.