An Example of Grade vs. Quality
November of last year (2021) I brought some pears back from my trip home to Missouri. Realizing that I couldn't eat them all, even baking two pies from them, I ordered a food dehydrator so I could save some for later snacking. I found one online with nearly 5 starts and plenty of positive reviews. It's a straightforward device, which can sit on my kitchen countertop, and which has a few racks so layers of fruit can be dried at the same time. To turn it on, all I have to do is plug it in. There is no on/off switch, standby mode, remote control, temperature setting, or anything else. It's either on or off, based entirely on whether or not it's plugged in.
Someone else might have need for a lot of different features, but I don't. That food dehydrator does absolutely everything I need it to do, and it's easy to clean. I hope it lasts a good long while. This countertop appliance would be accurately described as low grade, but high quality. That is, it's an extremely basic model with no frills, but it precisely meets all my expectations. It would be possible for me to buy a more expensive and feature-rich model which would be high grade, but if features didn't work properly or it gave me other problems, it would be low quality. Then again, maybe it'd be fine, with plenty of features that all work as expected. In that case it would be both high grade and high quality.
Hopefully that makes sense to anyone looking to understand grade and quality. With this explanation in mind, think about other products, from food to electronics and all points in between, and mull over for yourself what makes for high or low rankings on grade and quality for each. In doing so you might be surprised by what you discover.