: In the field of computer science, a data structure is a data management, storage and organization format which enables an efficient access and modification. Data Extraction can be defined as retrieving data from source and then further utilizing it as per required necessities. Data Extraction is a process of extracting unstructured, structure semi-structure data from the user requirement based upon data warehouse or web or any type of automation level etc. Structured data is data that has been organized into a formatted repository, typically like a database, so that its elements can be made addressable for more effective processing and analysis. Unstructured data (or say unstructured information) is the information that either does not have a predefined data model or is not organized in a pre-defined manner. This paper will review and give a basic ideal understanding concept overview to existing techniques on data extraction for data on different environment. This review is aimed to discuss different data extraction approaches together with the basic tools algorithms for extracting favour data from different sources mainly such as OCR, Data Storage and analysing Methods, WEB Based techniques etc.