The main difference between Album and Gallery is hierarchy structure. Each added album can contain a number of entries (images, videos and so on…). Imagine you showcase works in the layout and you show covers on the website. At the same time you want to show work related other pictures or resources when the item is clicked. Then you should use Album structure. But if you want to show a simple gallery, then you should pick the Gallery layout structure. In other words, the Album is a two level hierarchy structure, whereas the Gallery is a single level.
