php - PDO main variable naming. Is it a connection, or a handler, or a handle? -

in code below there variable named "dbh". describe variable "connection", "handler", "handle" or else? might seem trivial , non important question, know correct term call variable know call when talk it.

try {     $dbh = new pdo("mysql:host=".db_server.";dbname=".db_name, db_user, db_pass); } catch(pdoexception $e) {     echo $e->getmessage(); } 

it's "handle" db class. in case, it's referencing pdo class instance, , think that's should call it.