Space
$aaa \ bbb$
aaa \ bbb
To represent a space, you can use a combination of "\ " and a space. Using just a space character alone may not display as intended.
$aaa \quad bbb$
aaa \quad bbb
To represent a wider space, you can either repeat the space multiple times or use the "\quad" command. The term "quad" is derived from "quadrat," which refers to a square frame. In applications like Word, a space is sometimes represented as a square shape, and imagining that can provide a clearer understanding of the command.
$aaa \qquad bbb$
aaa \qquad bbb
The more "q"s you add to "quad", the wider the space becomes.
$aaa \hspace{ 10pt } bbb$
aaa \hspace{ 10pt } bbb
The command "\hspace" is used to create horizontal space. It allows you to specify the desired size of the space you want to create.
$aaa \! bbb$
aaa \! bbb
By combining the commands "\" and "!", you can reduce the space between two elements.
$\begin{eqnarray} aaa \\ bbb \end{eqnarray}$
\begin{eqnarray}
aaa \\ bbb
\end{eqnarray}
By doubling the backslash "\" or using the command "\cr", you can create a line break or new line. The "cr" stands for "carriage return," which represents the control character that moves the cursor to the beginning of the line.
$\begin{eqnarray} aaa \\[5pt] bbb \end{eqnarray}$
\begin{eqnarray}
aaa \\[5pt] bbb
\end{eqnarray}
After doubling the backslash "\" to indicate a line break, you can specify the width of the line break using additional commands.
$\begin{eqnarray} & & \frac{1}{2} +\frac{1}{3} +\frac{1}{6} \\[ 5pt ] &=& \frac{3}{6} +\frac{2}{6} +\frac{1}{6} \\ &=& 1 \end{eqnarray}$
\begin{eqnarray}
& & \frac{1}{2} +\frac{1}{3} +\frac{1}{6} \\[ 5pt ]
&=& \frac{3}{6} +\frac{2}{6} +\frac{1}{6} \\
&=& 1
\end{eqnarray}