Supervisor vs Advisor recommendation?

[Hima]

I am confused about one recommendation. The supervisor doesn't have a great profile personally but I worked a lot with her and she might write me a better LOR than the professor whom I have not worked with. Whom should I ask?

[fuzzylogician]

See about having your direct supervisor co-write the letter with the professor. That way, you get the details from the supervisor and the signature that counts from the professor. (I am assuming here that the professor is both your and the supervisor's boss, although that wasn't entirely clear from your post.) 

[Hima]

2 hours ago, fuzzylogician said:

See about having your direct supervisor co-write the letter with the professor. That way, you get the details from the supervisor and the signature that counts from the professor. (I am assuming here that the professor is both your and the supervisor's boss, although that wasn't entirely clear from your post.) 

I am sorry I didn't give all details. They are completely different entities. They do not know each other too.

[fuzzylogician]

1 hour ago, Hima said:

I am sorry I didn't give all details. They are completely different entities. They do not know each other too.

Alright, so why don't you give us the relevant details? What can the letter from the supervisor say and what can the letter from the advisor say? Does the supervisor have a PhD-holding supervisor of her own who could co-sign the letter? What other letters do you have? 

[Hima]

@fuzzylogician The letter from the supervisor would talk about a web dev project I did under him in the summer. He does not hold a PHD nor does have someone who can co-sign it but he holds a high position in and MNC. The advisor is someone with a great research background but the drawback is that I didn't work much with him, just a semester project which got over real quick. 

[fuzzylogician]

43 minutes ago, Hima said:

@fuzzylogician The letter from the supervisor would talk about a web dev project I did under him in the summer. He does not hold a PHD nor does have someone who can co-sign it but he holds a high position in and MNC. The advisor is someone with a great research background but the drawback is that I didn't work much with him, just a semester project which got over real quick. 

One last attempt before I give up: what other letters do you have? The question is how this third letter fits in with the other two. Though if I understand correctly both letters will be from people who've only known you briefly (one summer and one semester, respectively) and will talk about one quick project. If that is the case, it seems like the person with a PhD and research background is a better choice. Although of course you also didn't tell us what the letters are for (I'm assuming a research PhD here), and that, too, matters. 

[Hima]

@fuzzylogician, it is for Graduate applications. The other letters are from my professors/guides in ML and Concurrency related topics. The third professor I was referring to above comes from a compilers background. Thanks for all the replies btw.