Choose "System Report."
You can also get to this step quicker by holding the Option key and clicking "System Information."
Click on the "Power" option to view details about your MacBook's battery.
From here, you can see information like your battery's cycle count, full charge, and charge remaining. A battery cycle occurs when your MacBook's battery has been completely depleted. If your MacBook has consumed all of its charge cycles, it's fine to continue using it but you'll likely notice a dip in battery life.