reference: http://help-csli.stanford.edu/tex/latex-pagebreaks.shtml
\pagebreak[] use to start a new page at the end of the current line. Without arguments if forces a page break. With arguments of 0,1,2,3, or 4 it suggests that this is a good place to break. 4 being equivalent to no argument and forcing the break. No extra space is put at the end of the page. \nopagebreak similar to \pagebreak except it prevents a pagebreak at the end of the current line. I rarely use it. \samepage pretty much as the latex manual says. I rarely use it. \newpage forces a break at the point and puts in space as needed at the end of the page. \clearpage similar to \newpage but figures are also printed \cleardoublepage similar to \clearpage but will force another page if needed so the next page with print is odd numbered.