To compare two people/things, we use the comparative form (e.g., bigger, longer, better, worse, more glamorous). To compare two or more people/things, we use the superlative form (e.g., the biggest, the longest, the best, the worst, the most glamorous). Examples from the text: 'Jim is taller than Tom.' (comparative), 'Andrew is the tallest boy in our class.' (superlative).