tipos de href para php

<br><b>Trailer: </b>".$row['trailer']."

<a href="uploads/<?php echo  $row["arquivo"]; ?>" target="_blank"><img src="uploads/<?php echo  $row["arquivo"]; ?>" width="100%" class="img-fluid"></a>

<a href='<?php echo $row["url"]; ?>' target="_blank"><?php echo $row["titulo"]; ?></a>

<a href='".$row['trailer']."'>".$row['trailer']."</a><br>

<a href='".$row['trailer']."' target='_blank'>".$row['trailer']."</a><br>

<td><a href="<?php echo $row["website"]; ?>" target="_blank"><?php echo $row["website"]; ?></a></td>