Leading is the space between lines, measured from the baseline of one line to the baseline of the line above it. In the Creative Studio, you can apply leading to a whole paragraph or to selected lines within a paragraph. To change the line height:
Click the text frame to open the Text editing toolbar.
Select the part of the text, then change the line spacing in either of these ways:
Enter a number in the Line height field (under the Text section).
Use the arrows to increase or decrease the line height.
Save the page when you're done.