What's the difference among those groups?

Question

In python. The metachracter of | means to match one of the characters in a pettern. so :
(1|2|3|4|5) will check for one match of those chars.
[1-6] will do the same in that range.
[12345] I think this one will do the same. sorry, I'm just confused. Help me and sorry for the long spech lol.

Answer 1

Thanks for your answer, but it was a test for me to point out the inequivalent expression and the answer was [1-6] and I didn't understand why. more explanation needed here. Thanks in advance.

Answer 2

the only difference is that the first one (1|2|...|5) is in a capturing group which can be referenced later. besides that they are all the same

Answer 3

well [1-6] is the only one that includes the number 6. but thats all