{titles} is about typesetting document titles, usually with the help of \maketitle or the titlepage environment. A popular package is {titling}.
To influence the formatting of \maketitle or the titlepage environment, you can use the titling package, which also lets you use the \title, \author and \date information throughout the document.
sectioning is about commands like \chapter or \section, which in turn can be modified with the titlesec package.