ETL stands for extraction, transform and load. So first the readout of data from multiple, mostly differently structured data sources, followed by the transformation or alteration of the data into a different format, and finally the reloading of the data into a corresponding target database. In this way the different data are cleaned and standardized.
Hypermedia is a nonlinear medium of information whose main characteristic is hypermediality, the linking of information points by means of hyperlinks. Hypermedia can comprise any type or form of media, although the best-known is hypertext. Hypermedia is often incorrectly understood as or confused with multimedia.