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.
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.
Examples: From the Overview tab:
From the Storage tab: