Drupal includes a module called Media - for most sites, you'll turn it on and use it to place images, videos, documents, and then when you're actually using all of those resources on your site, you'll find that with images, you can create the Alt text once and it's just automatically there when you use that image.
You can also create Views directly with media rather than putting the media objects in a content type (e.g. a gallery of images or videos) using just the Media, with in this case, a Taxonomy field added on to filter and group the videos.