Footnote is a word of German origin (German Fuss-foot, notes - notes), which indicates a note, a note placed on the bottom of the page of text. Footnotes are used for additional information in your document. Clicking on a reference to a footnote in the text, Word allows transfer to the part where the additional inforamation is. Word automatically monitors the location and numbering of footnotes, this makes it easier to work.
Selection of footnote is performed by clicking from REFERENCES TAB.