[Tex/LaTex] Vertical space and its size

spacing

I don't know if somebody has already asked, but:
how should I do a vertical space of a size of a half/quarter of page?

Use a \vspace with the appropriate fraction of \textheight or \paperheight...

\documentclass{article}
\usepackage{lipsum} %for dummy text
\begin{document}
\lipsum[1]
\vspace{0.5\textheight}
\lipsum[2]
\end{document}


As egreg says in the comments, the space will be removed if it occurs at the top of a page. If you want the space in that case, just use \vspace* in place of \vspace.