The character style called "Normal" is present by default in every document and has a special significance: it is the default style for the text. When you start entering text in a new document, the "Normal" character style is automatically used for the text.

If you change the "Normal" character style – for example, the font – the font of the entire text will be changed (except for text that you have formatted manually in a different font via the ribbon tab Home | group Character). Furthermore, subsequent text will appear in this default font which you have redefined as the "Normal" character style for the document.

If you want to apply a different character style to your existing text instead of the default "Normal" style, select the text and follow the instructions in Applying character styles. The selected character style then also becomes effective for subsequent entries that you type directly after the text.