Both columns use the same font size and leading (line spacing). However, the text on the right uses spacing after each paragraph that is slightly less than double hard returns would allow. Additionally, the subheading has a small amount of space added before it, to set that section apart from the preceding text without leaving the excessive empty space found on the left where triple hard returns are used.
The dialog boxes at the bottom of the illustration show some of the formatting options available in Adobe InDesign and QuarkXPress. The highlighted portion sets the amount of spacing before and/or after a paragraph.
Professional typesetters, designers, and desktop publishers should use paragraph formatting to put space between paragraphs. Save the hard returns for typewriting, email, term papers, personal correspondence, or manuscript submissions that specify typewriter-style formatting. For everyone else, do whatever makes you feel good.