This video covers both databases because GeoRef is integrated into GeoScience World, but you can also use them on their own, so it can be a bit confusing to talk about them separately. This video goes over how to do a search including the different search options in each database, and how to access the full text PDF.
Engineering Village has a few components to it that are relevant to different areas of study and you can search these together or separately. This video covers a basic search applicable to any portion of Engineering Village and looks at the different filtering options you can use to refine your search. It also examine an article record, goes over how to evaluate it and how to share and save resources with permalinks. Finally as Engineering Village is just an indexing database, and the full text is not stored there, it'll show to use the Find It button to gain full access to the PDFs.
This video covers general searching and the citation tracking features that set Web of Science apart from other databases. Web of Science covers quite a few subject areas, across the sciences and engineering; it actually consists of several separate collections you can search separately or all at once. This video goes over the basics that are applicable to any of the collections.