A comment is a line that is not executed in output. It is only used to read by the developer for an idea about the code .
PHP supports three ways of commenting:
//echo " This line is commented"
#echo " This line is commented "
/* echo " This line is commented " */
<h4>hello all of you</h4>
//echo " welcome to teknowize"
#echo "my name is sumit"
print "i use two different method of commenting in PHP."