Alignment Is the most important concept

Keeping things lined up is as important in Web design as it is in print design. That’s not to say that everything should be in a straight line, but rather that you should go through and try to keep things consistently placed on a page. Aligning makes your design more ordered and digestible, as well as making it seem more polished.

Do you have any examples of good and bad alignment ?

Ya I do agree to you but there is one more thing I want to add i.e a good design allows easy tracing of errors & rectify them because in a tangy design its quiet difficult to trace & rectify errors