Hello,
I'm learning how Bitcoin address is generated and I don't understand one thing.
My source is the following
http://gobittest.appspot.com/Address
https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses

What I dont understand is step 2, hashing public key
using SHA-256 hashing function.

Both mentioned sources have the output of the SHA-256
but If I try any other hash generator the result is different

Can anyone explain why? Is the public key hashed multiple times or why?
thank you very much.