Paraphrasing methods identify, generate, or extract phrases, sentences that convey almost the same information. Different worded sentences may bear the similar meaning and can be identified by paraphrase identification. Paraphrase detection has importance as it contributes to various NLP tasks like Text summarization, Document Clustering, Question Answering, natural language inference, information Retrieval, Plagiarism Detection, Text Simplification. The motivation of the paper was to summaries all available approaches for paraphrase detection, resources and recent trends.

Keywords : NLP, Sentence Encoding, Statistical Similarity, Semantic Similarity,Attention, Machine Translation, Classification.