This creates a sequence (collection) of your choosing.

Integers

If you need a sequence of numbers for iteration or numbering, use Sequence:

Sequence{0..20}

It will create a collection of integers.

Strings

Sequence{'String', 'EmailAddress'}

It's not necessary to use Sequence for this - Set or Bag works equally well.

If you want to create a list of arbitrary numbers, you can use the Set operator.

(It might also be called an array or list.)