Question Answering (QA) systems are considered an advanced form of information retrieval that enables asking specific questions by humans and the system infer answers using natural language queries with deeper knowledge understanding mechanisms from huge amount of data instead of having the user search all documents himself. As what a user really wants is often a precise answer to a question by consulting documents on the web or using special knowledge base.
Although many systems have been developed over the past years, it remains a challenge that most systems yet require improvements to increase the accuracy for correct interpretation of the question and provide a good exact answer to user questions. This paper presents a short study of the generic QA framework and aims to survey some of the current state-of-the-art Question Answering systems in different domains and makes a comparison between all of these systems based on some identified criteria in literature.