[gTen]

To explain things simply, odin is the tool Samsung uses to flash out phones.

Heimdall is a reverse engineering of Odin's protocol that creates an open source cross-platform alternative to odin.

Aka think of it as a dev community version of odin. Its not meant specifically for devs though, anyone can use it.

It works on all platforms including windows. Both accomplish the same thing so it boils down to preference for wndows users.