What to KnowEasiest method: It's printed on the bottom of the laptop.Alternatively, go to Apple Menu > About This Mac, note the model identifier, and cross-check on Apple's support site.You use the model number to check compatibility with software, accessories, and hardware upgrades.
Your MacBook's model number is on the packaging the laptop came in, but you have other ways to get the information if you didn't keep it. Here's how—and why—to get the model number for your MacBook
Where to Find the Model Number on a MacBook
The first and easiest thing to try is to look at the computer itself. Flip your MacBook over; the model number is in the fine print at the top of the case. You can use this number for most of the queries you might need to make about your Mac.
The same area will contain your MacBook's serial number, which can get you even more information.
How to Use About This Mac to Find Your Mac's Model
If you have trouble seeing the tiny letters on the MacBook case and your Mac starts up, you can find the information elsewhere.
Click the Apple menu in the upper-left corner of your screen and select About This Mac.
On this screen, you'll see model information, which shows the type of laptop you have (i.e., MacBook, MacBook Pro, or MacBook Air), the display size, and the year Apple introduced it. If Apple brought out multiple models the year your computer debuted, you might also see a modifier; for example, "Mid 2015."
You can also find your MacBook's serial number on this screen.
The type and year information should be as good as a model number to get the information you need about your computer. But if you want further information, click System Report.
Make a note of the Model Identifier on the next screen.
Now, you'll go to Apple's support site to get the model number. You'll go to a different page depending on whether you own a MacBook, MacBook Air, or MacBook Pro.
Search for your Model Identifier on this page; underneath it, you'll see entries under a Part Numbers heading.
The Part Numbers entries are not the model number of your MacBook, but they are specific to each type. Technicians usually use this information when they're making repairs.
Why Would You Want Your MacBook's Model Number?
The model information of your MacBook can help you do several things. For example, to upgrade the memory or storage, you want to make sure you're getting RAM or other hardware compatible with your machine.
Similarly, you might want to look at accessories for your MacBook. Usually, compatibility will depend more on the version of the macOS you're running. But for products like cases, external keyboards, and other size-specific things, you'll want to make sure you get the correct item, and knowing your model information can help.
You may also want to see if you still qualify for warranty service. In that case, the serial number will be more valuable than the model, but if you don't remember how long it's been since you bought your MacBook, this information will show you immediately.