You can take the advantages of the System Information app to check a summary of information about your Mac hardware, software and network.

The System Information app delivers detailed qualifications and other information about your Mac hardware and software, like your network and external devices. In some versions of OS X, this app is named System Profiler.

Select Apple menu > About This Mac. This opens an overview of your Mac, containing your Mac model, processor, memory, serial number and version of macOS. In order to see the greater detail prepared by the System Information app, click the System Report button.

Actually when you straightly open System Information, push and hold the Option key and choose Apple menu  > System Information. You can also use Spotlight to find System Information or open it from the Utilities folder of your Applications folder.

Don’t forget that the System Information opens to a system report for your Mac:

Choose items in the sidebar to check information about each item. like:

  • The Hardware section displays your Mac serial number
  • The Memory section displays how much RAM is installed in each internal memory slot.
  • The Software section displays which startup disk (boot volume) your Mac is using.
  • The Network section displays details such as your IP address, the connections allowed by your macOS firewall, the signal strength of nearby Wi-Fi networks and more.