Is there any difference between
jQuery(\'#id\').show() and jQuery(\'#id\').css(\"display\",\"block\")
and
jQuery(\'#id\').
Yes there is a difference in the performance of both:
jQuery('#id').show() is slower than jQuery('#id').css("display","block") as in former case extra work is to be done for retrieving the initial state from the jquery cache as display is not a binary attribute it can be inline,block,none,table, etc.
similar is the case with hide() method.
See: http://jsperf.com/show-vs-addclass