You’re absolutely correct, the terms have been muddled and people, even ‘experts’ confuse the terms. The book: The Mind Illuminated is a great modern day guide

You’re absolutely correct, the terms have been muddled and people, even ‘experts’ confuse the terms. The book: The Mind Illuminated is a great modern day guide on meditation and the different stages of progression one may hit along the way. While meditating, one typically develops two skills: 1. Samadhi: stable attention, being able to focus on the meditation object without forgetting or getting distracted. 2. Sati: mindfulness. Best translated to something like peripheral awareness. Samadhi is focus on the book you’re reading without losing your place because the dog is barking. Sati is being aware of the context of your environment (dog barks, birds chirping, the feeling of your butt against your chair) without losing sustained attention on the book. One cannot really develop mindfulness without sustained awareness, as otherwise you context switch from the soup you’re eating to that thing Brett said at work, to back pain, back to the soup. Training those two skills gives a person the ability to better focus their attention on things deliberately while keeping enough in your conscious periphery that you have enough context to switch attention to other things that matter.