Alternate art Pokémon cards are cards that deviate from the usual art style in a set. Usually most cards in a set will share a common art style or theme, while these cards have an alternative look to them. In older sets of the Pokemon TCG, you’ll find that many cards in the same set had a variety of art styles, but nowadays sets tend to look more uniform. These alternate art cards allows for sets to feel consistent while still having cards that stand out from the crowd. This technique started in the Sword and Shield: Battle Styles set.
The card on the left is an alternate art Galarian Moltres V while the card on the right is a normal Galarian Moltres V. Just by looking at these two cards you can tell one is more rare because we don’t see many Pokémon cards that look like the one on the left. Another thing to note for people that not only like collecting, but those that play the TCG, these alternate art cards have the same moves. So these cards do the same thing, they just look different and it’s a good way to flex on your opponents.