A style is a collection of all formatting information, which
you want to save and then apply on the document. For
example, following details of Font can be stored as a
style with the name ‘Title style’. 

Now you can use and consistently apply Title style
to all titles of the document. To change the style of
Title in a document, you just need to update the Title
style and apply it to the document. Similarly, to change
the format of the complete document, just change the
style applied to it. Using Style allows you to shift your
focus from appearance of the document to the content
of document. This chapter will help you learn how to
create and apply styles in Libreoffice Writer.