Because centered alignment and right alignment have limited applications when it comes to continuous text, we are essentially concerned with the pros and cons of using Left or Left Justified type, and the main difference between themwhat happens to the leftover space. On every line of type there will be leftover spaceunless, like Jack Nicholson in The Shining, you're just typing the same line over and over. With Justified type the extra space is distributed between the words and varied to give you lines that are exactly the same width. With left-aligned type, the extra space is added at the end of the line, giving you lines of varying width.
Left-aligned type has the following characteristics:
Justified type has the following characteristics:
How InDesign Justifies Type