Lists in which each item is presented in its own paragraph preceded by a marker are usually much easier to read than lists that are separated by commas. Such markers (usually little boxes, circles, arrows, etc.) are called bullets.
Working with bulleted lists is an easy task for Presentations users. The placeholders in the content area of most slide layouts are already preformatted for bulleted lists. Any text you enter in it will be automatically provided with bullets.
Alternatively, you can create lists with numbers instead of bullets. The paragraphs are then automatically numbered as 1st, 2nd, 3rd, etc.
Bullets can be enabled and disabled for each paragraph at will, and the formatting of bullets can be changed at any time:
To do so, use the icon 
on the ribbon tab Home | group Paragraph to directly insert predefined bullets or choose the path via the dialog box to apply individually created bullets. You can also use this option to remove bullets or to convert a bulleted list into a numbered list.
For more information on working with bulleted and numbered lists, see the following sections.