latex font size only a text code example
Example 1: latex text size
\Huge
\huge
\LARGE
\Large
\large
\normalsize
\small
\footnotesize
\scriptsize
\tiny
Example 2: latex default font size
\documentclass[12pt]{book}
\Huge
\huge
\LARGE
\Large
\large
\normalsize
\small
\footnotesize
\scriptsize
\tiny
\documentclass[12pt]{book}