Why is Coinbase charging me a fee?

I'm curious to understand why Coinbase is charging me a fee for my transactions. As a user of their platform, I've noticed that there's a certain percentage deducted from my trades, and I'm wondering if this is standard practice in the cryptocurrency industry. Could you please explain the rationale behind these fees and how they compare to other exchanges? Additionally, are there any ways to minimize or avoid these fees altogether? I'd appreciate any insights you can provide on this matter.