Data virtualisation is a way to data management that lets an application to fetch and shape data. without needing technical details about the data. Such as how is the source format, or where the location is and can provide a single customer view of the data.

Unlike the traditional extract, transform & load ("ETL") process, the data remains in place. Real-time access given to the source system for the data. This reduces the risk of data errors. The workload moving data around that may never use, and it does not attempt to impose a single data model on the data. The technology also supports the writing of transaction data updates back to the source systems. This concept and software is a subset of data integration. It is generally used within business intelligence, service-oriented architecture data services, cloud computing, enterprise search and master data management.

Some enterprise landscapes are filled with contrasting data sources. Including many data warehouses, data marts, and/or data lakes. Data virtualisation can bridge data across data warehouses, data marts, and data lakes. All without having to create a whole new integrated physical data platform. Existing data infrastructure can continue performing their core functions. While the data virtualisation layer leverages the data from those sources. This aspect of data virtualisation makes it necessary to all existing data sources. It also increases the availability and usage of enterprise data.

Data virtualisation may also be considered as an alternative to ETL and data warehousing. Data virtualisation is aimed at producing quick and timely observations from many sources. Without having to embark on a major data project with extensive ETL and data storage. Yet, data virtualisation may be extended and adapted to serve data warehousing requirements as well. This will need an understanding of the data storage and history requirements along with planning and design to incorporate the right type of data virtualisation, integration, storage strategies and infrastructure/performance developments.