It is important to have a record of some of the basic information about your Mac. You should collect the information when you first set up your Mac — update it whenever you update your operating system or change peripherals.
Click on the Apple icon at the left end of your menu bar and select About This Mac.
Record the information in a text file and save it to use when you have a problem. You can also create a screen capture and save it as a PDF file. I recommend that you create a special folder in iCloud or Dropbox called System Configuration and save the information there. This will ensure that it is available from your mobile devices in the event of a computer crash.
From the Overview tab:
- Model (e.g. Mac mini (Late 2012))
- OS version (e.g. macOS Sierra 10.12.6)
- Memory (e.g. 16 GB)
From the Storage tab:
- Storage (e.g. 1 TB)
- Free space on your drive (e.g. 650 GB)
Do you have a current backup? If so, what type:
- Time Machine
- Bootable Clone
- In the “Cloud”