- A source file is made up of text, formulas, and instructions (commands) to $LaTeX$.
- Commands start with a backslash () and tells $LaTeX$ something special.
- One-line comments start with %.
- $LaTeX$ disregards the way you input and position the text, and follows only the formating instructions given by the commands.
- $LaTeX$ notices when you put a blank space in the text, but it ignores how many blank spaces have been typed.
- There are two kinds of math formulas and environments
- Inline formulas; they open and close with $ or open with ( and close with ).
- Displayed math environments; they open with [ and close with ].
- Subscripts are typed with _ and superscripts with ^. Subscripts and superscripts should be enclosed in braces, that is typed between { and }.