This is a core block and thus available by default in Gutenberg WordPress editor. No download required.
WordPress Gallery Block in Gutenberg allows you to display multiple images in a more Organised form. It displays your images in a nice grid. This is a great way to display your photos.
Gallery Block Features
Gallery block has some useful features. In the toolbar, it has alignment options. From the sidebar settings, you can adjust the number of columns. It also has a crop option which makes all images equal size (if enabled). You can also adjust the link option to make your images linking to the media file, attachment page or none.
This is how the gallery look on frontend using the gallery block.
The gallery block added to a page.
This is how the gallery block looks after adding some images.
Gallery block grid columns option.
Gallery images without crop option enabled.