What are the minimum requirements for upgrading a system to macOS Sierra?

What four preparation steps should you take before upgrading a system?

How can you determine whether a Mac requires a firmware update?

What are the advantages and disadvantages of using a single-partition and multiple-partition disk with macOS?

How can you acquire the MacOS installer?

What options can you select during the MacOS installation?

When troubleshooting a failed macOS installation, how can you find out more about why the installation may of failed?