If you're not familiar with the characters of Captain Marvel or Carol Danvers you soon will be; there's a 'Captain Marvel' movie on the way this year, and the early signs suggest that it's going to be a blockbuster. Here's Danvers in comic book form and looking truly resplendent.
The story behind how Danvers became Captain Marvel is a little complicated, so we'll break down the basic facts for you. Once upon a time, Captain Marvel was a man named Mar-Vell, and Danvers was Ms. Marvel. Then Mar-Vell died, and Danvers decided that the best way to pay tribute to Mar-Vell was to become Marvel, and so she took on the mantle and became the new Captain Marvel. She paid tribute to her own past as a pilot in the Air Force when she designed her outfit, and made sure she didn't put her underwear outside her pants. That was an unfortunate style choice that Mar-Vell shared with Superman.