Is there a way to join 2 queries of distinct tables in a single query?

I would like to know if there is a way to join 2 queries of different tables in a single query?

For example, in the code below I have 2 queries in separate tables. However, is there a way to perform these 2 queries as a single, one at a time, instead of having to do 2 variables and two separate queries?

$query1 = mysql_query("SELECT cod_empresa, razao_social FROM tbl_empresa ORDER by razao_social ASC") or die(mysql_error());
$query2 = mysql_query("SELECT cod_tipo, tipo_publicacao FROM tbl_tipo_publicacao by tipo_publicacao ASC") or die(mysql_error());