As everyone else has said, it's used as an umbrella term for anyone who isn't straight and/or cis. Some people may feel more comfortable using "queer" rather than a specific label.
I almost always refer to myself as "kweer" but in a positive tone.I can't explain it but I don't like the word "lesbian".Kind of kweer isn':icon_biggt il
I use it to describe myself because I definitely don't feel straight, but there's a lot of weird things going on with my sexuality. It's easier to be less specific.
the lead singer of senses fail calls himself not gay but queer. I never understood that lol. I think he is gay and homophobic towards himself. That's just my opinion based off his explanation.
Queer is a nice way to identify when you know you aren't straight and/or cisgender. It helped me while questioning because I didn't know what to label myself but I knew I wasn't straight. Queer was comfortable because I knew that whatever I really was was encompassed by that term no matter what. But it also serves as a nice general term used by people who do identify as "bi" or "gay" or "agender", etc. as well. Personally I think it has a nice ring to it.
I prefer the term "queer" to "gay" so much as I get angry when I hear someone say something like "Oh, I didn't know you were gay," the term 'gay' used in the context meaning 'homosexual' offends me so much to the point that I'll scream "I HAVE NEVER BEEN GAY A DAY IN MY GODDAMN LIFE, FUCK YOU VERY MUCH!" So, yeah, long story short, I prefer being referred to as "queer," over "gay." So to me, it just means "gay."