1- What is the difference between

my @arr = ['a','b','c'];
and
my @arr = ('a','b','c');
[download]

?

The first line creates an array with one element: a reference to an anonymous array with 3 elements, 'a', 'b', and 'c'.

The second line creates an array with 3 elements, 'a', 'b', and 'c'.

2- In what doc am I supposed to find the answer at this question?

In addition to the ones other have mentioned, you should probably read perldoc perldsc, the data structure intro and perldoc perllol, the "arrays of arrays" tutorial which explains in great detail the structure you created in your first example. In the future, you may help yourself to answer questions like your second one by reading perldoc perltoc, the table of contents.

-sauoq
"My two cents aren't worth a dime.";