Note that list indexing starts by default at 0. You can actually change this by setting the special $[ variable.
Let's set up a list;
@names = (alpha, beta, gamma, delta);
$names[0];
Hashes are special lists in which you look up elements NOT by position, but by using a key string. Here's an example of initializing a hash:
%letters = ( A => alpha, B => beta, G => gamma, D => delta);
A single element is returned by accessing the hash through the key, as in $letters{G}.
You can get at the keys in a hash using the keys command, and the values by the values command.