What does the "bonus" mean? What makes it different from "extra?"

Native speaker’s answer
Rebecca
Here, "bonus" means something in addition to what is expected, but is usually good. In relation to money, it means an added amount to one's usual salary, often seasonal and based on work performance. It's different from "extra" because "bonus" emphasizes something good, but "extra" doesn't always mean extra of something good. Ex: We have extra work for you if you're interested. Ex: If she completes three years with the company, she'll get a bonus. Ex: Getting ice cream at the fair was a bonus!