Can anyone explain black lives matter and all lives matter

The previous answer is incorrect and I don't know why that person gave the wrong explanation. Here, Black and matter are not personal names. "Black lives matter" is a movement in contemporary America. It literally means "Black lives matter", but in fact it means "Black lives matter". This is the slogan of the entire movement, which satirizes the white supremacists' attitude towards black lives. contempt and disdain for their value. And "all lives matter" means "all lives are lives" and "all lives matter."