implode will join array data together as a string, contrast to explode where string is converted to an array , see explode

<?php
//string_implode.php
$var = array('This ', 'is', ' a string', ' contains', ' names');
echo "<br/>";
?>
<html>
<title> string_implode.php</title>
<body bgcolor="#E7F2F5" text="#000080">
<?php
echo implode("",$var);
?>
</body>
</html>
 

<?php
//string_join.php
$var = array('This ', 'is', ' a string', ' contains', ' names');
$var_implode =join(" ",$var);
echo "<br/>";
?>
<html>
<title> string_join.php</title>
<body bgcolor="#E7F2F5" text="#000080">
<?php
echo $var_implode;
?>

</body>
</html>