Sprite or texture?

[daemoth]

So, as long the game images are displayed flat on the camera, or at least it was stay put on the screen, it's considered as sprite, eh? And, the same goes for the main menu image, is it?

Yup, there are always exception like when a model is 2d. Like for example, Paper Mario. At that point, its at your discretion, are people more likely to search for it in the sprite or in the textures? For paper mario, the whole concept of the game is that everything is paper thus use sprites so they were put as sprites. If the whole world is 3d and the character is holding 2d model map, put it as a texture.
Same for the main menu, as long as there are no models involved, its a sprite.