The Pali word samādhi is usually translated as “concentration,” and that’s not a bad translation. But “concentration” has a furrowed-brow connotation. Perhaps a better translation would be “indistractability,” which unfortunately is not really an English word. What the Buddha is pointing to with the word samādhi is the ability of your mind to not become distracted—the ability of your mind to remain aware of a specific, chosen topic without unintentionally wandering off to some other topic.