Hello,
The various types of UTI are urethritis (infection or inflammation of the urethra), cystitis (an infection of the bladder and is the most common form of UTI), ureteritis (infection of a ureter) or pyelonephritis(infection of the kidney). This can happen with infection from above, or if reflux into the ureters is so bad that infected urine refluxes all the way to the kidney.
I hope it helps. Take care and regards.
Why do you ask? What symptoms are you having?