Big data refers to large volumes of structured and unstructured data generated from different sources and in different formats. These data volumes are so large that conventional data processing systems and techniques are unable to process and analyse them efficiently. Big data is characterised by the so-called "3 Vs": Volume, Variety and Velocity.

Volume: Big data comprises enormous amounts of information that are generated on a daily basis. This data comes from various sources such as social media, IoT devices, business transactions and scientific research.

Variety: The information contained in big data can be structured, semi-structured or unstructured. Structured data is stored in organised formats such as tables, while unstructured data is in the form of text, images, videos and other file types.

Speed: The speed with which data must be generated and processed is a key characteristic of big data. Companies and organisations need modern technologies and approaches to be able to access and react to this data in real time.

In order to utilise the value of big data, companies and researchers rely on modern analysis methods and technologies such as machine learning, artificial intelligence and cloud computing.