Alignment determines how text lines anchor relative to container margins:
The gold standard for left-to-right languages. Aligns neatly on the left margin, leaving an organic ragged right edge. Because every line begins at the exact same horizontal anchor, the reader's eye effortlessly returns to the start of each line.
Aligned along an invisible central axis. Leaves gaps on both sides.
Aligned to the right margin. Natural for right-to-left languages (Arabic, Hebrew). In Western layouts, use sparingly for numeric columns or short meta tags.
Forces text to touch both margins by algorithmically expanding word spaces. In digital web browsers without hyphenation dictionaries, this creates hideous 'rivers of white space' that severely disrupt readability and create barriers for people with dyslexia. Avoid in digital UI.
Level 3 · Elements of Design II