  The amount of text that is generated every day is increasing dramatically.
This tremendous volume of mostly unstructured text cannot be simply processed
and perceived by computers. Therefore, efficient and effective techniques and
algorithms are required to discover useful patterns. Text mining is the task of
extracting meaningful information from text, which has gained significant
attentions in recent years. In this paper, we describe several of the most
fundamental text mining tasks and techniques including text pre-processing,
classification and clustering. Additionally, we briefly explain text mining in
biomedical and health care domains.
