The BR element forces a break in the current line of text.
BR is needed because a line break in the HTML file does not cause
the browser to display a line break.
H1, H2, H3, H4, H5 and H6 elements are used to
make headings, which are usually rendered in a
large, bold font.
H1 specifies the largest font, H6 - the smallest.
The PRE element contains preformatted text. Visual
browsers should render preformatted text in a fixed-pitch font,
should not collapse white space, and should not wrap long lines.