Big data refers to datasets that are so large or complex that they're difficult to process using traditional data processing applications. Big data technologies are used to collect, store, and analyze large datasets to gain insights that would not be possible from smaller datasets. Big data is often used in conjunction with DL to solve complex problems. For example, DL models can be used to train on large datasets of medical images to develop more accurate diagnostic tools. Or, DL models can be used to train on large datasets of customer transactions to develop more effective fraud detection systems.