Data lake

A Data Lake is an unstructured place to put data. It’s usually meant for long term storage and infrequent querying. 

Companies are collecting more data than ever before (yada yada), but not all of it gets used immediately. A data lake is a place to drop data, in an unstructured format, usually for long term storage. Data lakes are easiest to understand in contrast to data warehouses, where schemas are defined in advance.