I am a beginner. Can anyone state what it means if anyone says "The aperture of the photo/pic is not correct."? I donot know what actually aperture means.
That statement means that he/she thinks that the aperture that was used during the capture was too narrow or wide. The aperture's size affects (among other things) the depth of field and the sharpness of the image. It could also mean that the exposure was incorrect and that it could have been compensated for using another aperture size.
Lastly statement "The aperture of the photo/pic is not correct." isn't really very helpful unless he/she explained why. Of this comment comes from a good photographer it may be worth asking why and what aperture should be used, but keep in mind that you are the photographer and decides what is the "correct" aperture for your photograph.