This group of actions transform the text, adding or deleting whitespaces between words, moving words between lines within the paragraph so to give to the text the necessary appearance.
For correct work of these actions it is necessary, before performance of operations it is correct to break the text into paragraphs. The paragraph for TextLab is the fragment of the text separated from other fragments in the empty lines. I.e. empty lines for TextLab are borders of paragraphs.