At the end of each statement,we will use a semicolon to seperate each statement.Php closing tag autometically implies a semiclon.So last line of a statment do not require a statement.
<?php echo "first statement";
echo "second statement"
?>
Closing tag is optional and some cases omitting the closing tag is very helpful.
1.using include or require function
2.unwanted whitespace will not occur at the end of file
3.add header any time
<?php echo "omitting closing tag";