For some people being strong means physical strength with lots of muscles
For others it's increased intelligence and strength in mental abilities such as meditating, remembering or concentrating. These people are mentally and intellectually strong.
There are the emotionally strong who can withstand almost any sort of hardship. They're able to center their minds on the positive.
Bravery is a characteristic of a strong minded person. This person fears nothing.
Saying no to peer pressure or a bad habit is a sign of a strong will.
For a lot of people love is strength
Bryan Ferry (with David Gilmour) Is Your Love Strong Enough
Sly and the Family Stone - Brave and Strong
What sort of strong are you?