I just subscribed to a subreddit and now I am told that I can show my "flair" on that subreddit. What is a flair? Then, a row below, I'm shown "what it does lo

I just subscribed to a subreddit and now I am told that I can show my "flair" on that subreddit. What is a flair? Then, a row below, I'm shown "what it does look like". What I see? My username. Way to go. Also, it's not a language problem. I am looking at my country's localized version of Reddit and that word has intentionally not been translated.