Okay, imagine you're playing dress-up with your friends. You have a costume that you really love, and all your friends really seem to like it too. In fact, they like it so much that they're asking you where you got it so they can buy one for themselves. But you don't want everyone to have the same costume as you, because then it wouldn't feel as special.
That's kind of like what private label is. It's when a store or company creates their own products, but they don't put their name on it. Instead, they put a different name on it - a "private label" - so that it looks like it's a different brand.
So if you go to a grocery store, you might see a bunch of pasta sauce jars on the shelf. Some of those jars might have the store's name on it, like "Safeway Tomato Sauce." But others might have a different name on them, like "Mr. Pasta's Favorite Sauce." That "Mr. Pasta's" brand isn't a real company - it's just a made-up name that the store came up with so that they could sell their own pasta sauce without it looking like it was a "store brand."
Private label products can be really good quality, and they're often cheaper than other brands because the store doesn't have to pay another company to make it. So the store can save money, and you can save money too by buying a cheaper version of a product that's just as good as the more expensive one. And if you really like a private label product, you can feel special knowing that not everyone else has the same thing as you.