Their origins maybe different but they have a lot in common... So here's how SAM and Cortana are similar:

1. Both SAM and Cortana are Natural Language Processors who can be instructed with either the user's voice or a text input... while the former has limited commands, the later is completely dependent on the internet for Speech Recognition.
2. Both can fetch you the Weather condition in your region.
3. While SAM can fetch you results from Bing, Google or Wikipedia... Cortana can get you info from Bing.
4. The two can help you with any reminders you need!
5. Favorites! Both SAM and Cortana learn things about you and try to respond with accordance to your tastes!
6. Both give you a great experience with your inbox.
7. They are classic Mathematicians, who can crack any problem for you. 

And Here's where They Differ:

1. SAM can play music and stream videos for you, which can be controlled by your voice too..
2. SAM let's you convert files into formats that SAM's text-to-speech reader can read out to you.
3. SAM let's you read and send emails.
4. SAM features a Keyboard of it's own, that just glorifies typing.
5. SAM allows you to play games with your voice.

Note: Cortana may be able to perform the following functions but it requires certain apps!

Verdict: Let's be fair it's a tie! Each one makes up for the shortcomings of the other!

Be sure to share your opinions with us in the comments below...