Lt renal stone in calyx. Meaning of it?

I have been given following report while doing full body checkup for joining a reputed company: : LIVER : Liver is normal in size and echopattern. No focal intra-hepatic lesion detected. Intra-hepatic biliary radicals are not dilated.Portal vein is normal in calibre. GALL BLADDER : Gall bladder appears echofree with normal wall thickness .CBD appears normal. PANCREAS : Pancreas is normal in size and echopattern. SPLEEN : Spleen is normal in size & echopattern. KIDNEYS : Both kidneys are normal in position, size and outline.Cortico-medullary differentiation of both kidneys is maintained. Lt renal stone in middle calyx – 3.9 mm , no hydronephrosis No evidence of renal stone or hydronephrosis on Rt side No significant free fluid is detected . URINARY BLADDER : Urinary bladder is normal in wall thickness with clear contents.. PROSTATE : Prostate is normal in size and echo-pattern. Impression : Lt renal stone in middle calyx – 3.9 mm , no hydronephrosis So, what is the meaning of it?