Texture page
A texture page is a single texture which is a composite of several smaller textures. Typically, the content creator will start with several meshes and their textures, and manually stitch the textures together such that they fit onto a single texture with the most efficient layout possible.
An important note when creating a texture page is that certain parameters are tied to the texture, such as whether the texture represents a normal map or a diffuse map, whether alpha blending or alpha masking is used, and so on. It is not possible to combine different properties into a single texture page. While an alpha masked texture could be combined with an alpha blended texture, the result will be an alpha blended texture and will lose the performance and visual benefits of alpha masking.