Lists: Enumerate, itemize, description and how to change them

Latex distinguishes between three different enumeration/itemization environments. Each of them provide four levels, which means you can have nested lists of up to four levels.

Enumerate:

\begin{enumerate}
\item ...
\end{enumerate}

The enumerate-environment is used to create numbered lists.
If you like to change the appearance of the enumerator, the simplest way to change is to use the enumerate-package, giving you the possibility to optionally choose an enumerator.

\usepackage{enumerate}
...
\begin{enumerate}[I]%for capital roman numbers.
\item
\end{enumerate}

 

\begin{enumerate}[(a)]%for small alpha-characters within brackets.
\item
\end{enumerate}

Itemize:

\begin{itemize}
\item ...
\end{itemize}

Itemization is probably the mostly used list in Latex. It also provides four levels. The bullets can be changed for each level using the following command:

\renewcommand{\labelitemi}{$\bullet$}
\renewcommand{\labelitemii}{$\cdot$}
\renewcommand{\labelitemiii}{$\diamond$}
\renewcommand{\labelitemiv}{$\ast$}

Amongst the more commonly used ones are $\bullet$ (), $\cdot$ (), $\diamond$ (), $-$ (), $\ast$ () and $\circ$ ().

Description:

\begin{description}
\item[] ...
\end{description}

The description list might be the least known. It comes in very handy if you need to explain notations or terms. Its neither numbered nor bulleted.

Example:

\begin{description}
\item[Biology] Study of life.
\item[Physics] Science of matter and its motion.
\item[Psychology] Scientific study of mental processes and behaviour.
\end{description}

And in a PDF it would look like this:

Nested lists:

Lists can be nested. In other words, it is possible to have a sub-list for an item of a list. Usage is straight forward, different environments can be mixed (see example) and the maximum depth (number of levels) is 4. Here is an example:

\begin{itemize}
\item First level, itemize, first item
\begin{itemize}
\item Second level, itemize, first item
\item Second level, itemize, second item
\begin{enumerate}
\item Third level, enumerate, first item
\item Third level, enumerate, second item
\end{enumerate}
\end{itemize}
\item First level, itemize, second item
\end{itemize}

The space between different items can be controlled with the \itemsep command (can only be added just after “begin”):

\begin{itemize}\itemsep2pt
\item
\end{itemize}