Working with Big Data reveals that testing is different compared to regular software. The challenges arise from the very attributes of data. Known as the three Vs, these are volume, velocity, and variety, often complemented with variability and value. Each of them poses specific challenges, and they can also create more problems through their synergies.
The definition of big is not restricted to a specific number. Some talk about Big Data measured in GB, while other projects deal with petabytes or zettabytes, depending entirely on their scope.