Open PowerPoint and move to the slide that contains the text you want to highlight. Once there, select the text by clicking and holding the left mouse button and dragging your cursor over the text.
After you select the text, a popup presents several different font options. Go ahead and click the highlighter icon.
Your text will now be highlighted.
You can also choose between several different colors, as well. If you’d like something besides yellow, click the arrow next to the highlighter icon. A menu will then appear, presenting several different colors. Choose the one you like best.
You can also find all of these options in the "Font" section of the "Home"tab.