While the first line of paragraphs isn't typically indented online the way it is in academic or some other types of writing, there may be times when you want to indent content for formatting reasons.
Since the CMS is essentially a series of Web forms, you can't hit TAB to indent the way you can in a word processing program. In a Web form, hitting tab essentially moves you from one field to another.
Therefore, in the CMS, if you want to indent a section of text, you place the cursor in front of the paragraph to be indented (the indenting applies to the whole paragraph) and click the Increase Indent button in the formatting toolbar.
If you need to remove an indent, you can't backspace or delete it in the same way you can in a word processing program, either. You need to hit the Decrease Indent button in the formatting toolbar to remove the indent.