Tutorial on "Video Summarization and Re-use Technologies and Tools", delivered at IEEE ICME 2020. These slides correspond to the first part of the tutorial, presented by Vasileios Mezaris and Evlampios Apostolidis. This part deals with automatic video summarization, and includes a presentation of the video summarization problem definition and a literature overview; an in-depth discussion on a few unsupervised GAN-based methods; and a discussion on video summarization datasets, evaluation protocols and results, and future directions.