If your Mac starts up to a circle with a line through it - Apple Support

A circle with a line through it means that your startup disk contains a Mac operating system, but it's not a macOS that your Mac can use. 

Have your Mac speak text that's on the screen - Apple Support

What does this problem means? : r/hackintosh

Organize files in folders on Mac - Apple Support

Apple locked my Mac Pro

Apple locked my Mac Pro

Pick up where you left off with Handoff on Mac - Apple Support

Mac OS install on AMD Ryzen (VMWare) Opencore AMD OS X - Empowering your Mac with AMD Innovation.

Mail app not working on Mac? Here's how to reset it

Change a password or user picture on Mac - Apple Support

Cancel sign what does that mean - Apple Community

How to Start Up in Single-User or Verbose modes in macOS