<p>It all depends on the problem that you are trying to solve, the data available to you and the underlying domain. Lets get to it one by one:</p>

<p><strong>Type of Problem</strong><br>
There are multiple types of question answering systems, like one word answers based on extract the exact answer from various sentences, or returning the most similar sentence from a list of sentences based on the question asked by the user, using various similarity and embedding techniques. I think this paper : <a href="https://arxiv.org/abs/1506.03340" rel="nofollow noreferrer">Teaching Machines to Read and Comprehend</a> should be a good place to start getting an idea about such systems.</p>

<p><strong>Dataset</strong>
Next comes the dataset for such systems. Now there are various datasets available for question answering systems like :</p>

<ul>
<li><a href="https://rajpurkar.github.io/SQuAD-explorer/" rel="nofollow noreferrer">SQuAD dataset</a></li>
<li><a href="http://www.cs.cmu.edu/~ark/QA-data/" rel="nofollow noreferrer">QA dataset based on Wikipedia Articles</a></li>
<li><a href="https://research.fb.com/downloads/babi/" rel="nofollow noreferrer">Facebook bAbI dataset</a></li>
<li><a href="http://allenai.org/data.html" rel="nofollow noreferrer">AllenAI dataset based elementary Science question </a></li>
<li><a href="https://datasets.maluuba.com/NewsQA" rel="nofollow noreferrer">NewsQA datset</a></li>
</ul>

<p><strong>Methodologies</strong><br>
Well there are multiple ways to go about solving this problem. It would be difficult to list all of them in one answer, but I can provide you some references:</p>

<ul>
<li><a href="http://cs.umd.edu/~miyyer/data/deepqa.pdf" rel="nofollow noreferrer">Deep Learning for Question Answering</a></li>
<li><a href="https://www.slideshare.net/sujitpal/deep-learning-models-for-question-answering" rel="nofollow noreferrer">Various Deep Learning models on Question answering</a></li>
<li><a href="https://rajpurkar.github.io/SQuAD-explorer/" rel="nofollow noreferrer">SquAD dataset Leaderboard</a></li>
<li><a href="https://arxiv.org/abs/1507.02628" rel="nofollow noreferrer">Question Answering based on Word Alignment</a></li>
<li><a href="https://web.stanford.edu/class/cs224n/reports/2761224.pdf" rel="nofollow noreferrer">Attention Based Question Answering</a></li>
<li><a href="http://ai2-website.s3.amazonaws.com/publications/tableilp_ijcai_2016.pdf" rel="nofollow noreferrer">Reasoning-based QA</a></li>
</ul>
Which technique is used in Auto Answering user queries in Artificial Intelligence?
<p>I have a paragraph, system has to understand it and it should answer all the questions asked by the user. Please name the techniques and methodologies.</p>