A colon looks like this “:”

When to Use a Colon

To introduce a list

When introducing a list, use a colon, especially if the introduction contains phrasing such as “the following” or “as follows.”

The database includes:

* Reports

* Forms

* Tables

Before explanatory text

Use a colon to indicate that the initial clause will be further explained or illustrated by information that follows the colon.

Note that the colon serves as a substitute for phrases such as “in other words,” “namely,” or “for instance.”

The research was conclusive: aerobic exercise results in improved mood and appetite in adults of all age groups.

After an introduction to a statement or question

Remember this cardinal rule: Never reboot your system until you have saved all of your files.

When Not to Use a Colon

To introduce a figure or a table

The following figure shows the parts of the editing window.

In a list introduced within a sentence

Do not use a colon before a list introduced by “includes” or “are” within a sentence.

The base colors that are used in four-color printing are cyan, magenta, yellow, and black.