One stack cable connecting two switches.
SW-1#sh switch stack-ring speed
Stack Ring Speed : 16G
Stack Ring Configuration: Half
Stack Ring Protocol : StackWise
Two stack cables connecting two switches
SW-1#sh switch stack-ring speed
Stack Ring Speed : 32G
Stack Ring Configuration: Full
Stack Ring Protocol : StackWise
Each 3750 switch’s back has two stack ports 1 and 2.
Suppose you want to connect two switches with two stack cables:
1st switch port 1 connects to 2nd switch port 2.
1st switch port 2 connects to 1st switch port 1.
The stack cables will be crossed.
cyruslab 
Dear Cyrus,
Thanks for your help to improve my knowledge.
Hi Ahmed, I am glad this post helps. 🙂