These nodes are for working with text.
These nodes use the UTF-8 encoding for the Unicode character set. This means that they can handle ASCII characters (such as the English/Latin alphabet) as well as other characters, such as accented characters and non-Latin alphabets.
You can enter text that has multiple lines (line breaks) into a text input editor. Do this by composing your text in a basic text editor (such as TextEdit), then copying and pasting it into the input editor.