An upside is a good thing that happens, but its opposite is also important. The downside refers to the not-so-good part of a situation.
When we talk about the downside, we usually mean the less desirable or negative aspect of something. For example, let's say you're thinking of buying a new house. The upside might be that it's in a great neighborhood with good schools and parks nearby. But the downside could be that it's a bit more expensive than you'd like, or maybe it needs some repairs before you can move in. We often use the word "downside" when we're weighing the pros and cons of something. So, if someone says "What's the downside to this new job?" they mean what are the potential problems with it?
A disadvantageous aspect of something that is normally advantageous.
Example: The downside of obtaining a higher rank is that far more work is expected.
