Howard Gardner proposed the theory of multiple intelligences in 1983. The term "multiple intelligences" is used to talk about a theory that tries to classify the different ways that students can learn and understand things.
Metacognition is the ability to reflect on one's own cognitive processes and the ability to think about and change your own thought processes. A big part of metacognition is being aware of yourself as a learner and being able to evaluate your own learning style and figure out where you could improve.
Having a "growth mindset" means you think you can develop your skills and abilities further. If you have a growth mindset, you enjoy a good challenge, refuse to let setbacks define you, and instead use them to learn and improve.
Grit is a trait that is shared by people who keep working toward a goal even after a lot of setbacks and delays. It's the willingness to keep going no matter how difficult things get or how long it takes to reach your ultimate goal.
Grit is a trait of someone who is able to stay focused on a long-term objective despite several setbacks and challenges. Hard work, perseverance, discipline, dedication, and sacrifice are all necessary to achieve the most desired outcomes.