Welcome! Yes, a tuxedo DSH (domestic short hair). That actually means a short haired cat of probably mixed background. With cats, unless there are papers, it is really, really hard to tell the exact breed, and MOST of our cats have mixed heritages.
I LOVE the little mittens on her front feet. She's a doll!
Tuxedo means the pattern, alike a coat - usually black and white, although it MAY be a tabby and white. Thus Its not a breed - purebred cats may too carry a tuxedo, for example Norwegians Forest cats not seldom are tuxedos.