[DBI-users] what's <<"SQL" do?

Quick question, I have a chunk of code from a previous coder:

$member = $dbh->selectrow_array( <<"SQL" );
SELECT whatever FROM DATA
SQL

I'm not familiar with the syntax? Is the <<"SQL" string just replaced
by the text up to the "SQL" on a line by itself so functionally it
could
be written:

$member = $dbh->selectrow_array
("SELECT whatever FROM DATA");

and if so why do it the other way, perhaps because it's easier to
form a long length query?

$member = $dbh->selectrow_array( <<"SQL" );
SELECT whatever ...
more
more etc.
SQL

Don