A download containing files from multiple collections that can be retrieved at once. Data is available in bulk if the entire dataset can be downloaded easily and efficiently to a user’s own system. Conversely it is non-bulk if one is limited to getting small parts of the dataset, for example, are you restricted to a few elements of the data at a time and therefore require thousands or millions of requests to get the entire dataset. The provision of bulk access is a requirement of open data.

Source: ODH.