What is meant by list[::2] in Python ?

Question

I was wondering when I came across a question in Python where it asked about the answer of above . it seems like a list operation but I didn't understand

Answer 1

https://docs.python.org/2.3/whatsnew/section-slices.html
15 Extended Slices

Answer 2

I found the most effective way to learn list slicing is just to experiment

https://code.sololearn.com/cXNzv56rgiyL/?ref=app

Answer 3

list[a:b:c] gives a new list by taking every c element from a to b.

Example:

nums = [67, 46, 28, 59, 32, 48, 19, 46]
nums[2:5:2]
[28, 32]
If a and b are omitted they default to the beginning and the end of the list