Voiceover is a screen reader that is embedded within each and every Apple product. It allows blind and visually impaired people to use Apple products such as the mac, iPhone, iPad, Apple Watch, iPod, HomePod, and even Apple TV. This means that it is available on Mac OS, iOS, iPad OS, Watch OS and TV OS.
obviously, the fact that the same screen reader is available on such a wide variety of products means that it create some sort of an “ecosystem”, as it exhibit many similarities to make the user experience seamless across different products. However, the fact that these products are so different means also that it won’t work exactly in the same way, and in deed its usage is slightly different on a per-product basis.
VoiceOver offers both Braille and speech support. Apple provides detailed documentation about its usage and configuration on each of its product.