VoiceOver is a built-in screen reader that describes aloud what appears on your computer screen: it speaks the text that’s in documents and windows. Using VoiceOver, you control the computer primarily with a keyboard, braille display, or trackpad, instead of the mouse.
Narrator is a native Window 10 screen reader. It will generally read what is selected or outlined visually on the screen. Use keyboard keys to control Narrator's options and interactivity.
The ChromeVox screen reader is an extension to Chrome that brings the speed, versatility, and security of Chrome to visually impaired users built using only web technologies like HTML5, CSS and Javascript.