Every Booster Pack is initially printed as 1st Edition for a limited period, after which they are replaced by Unlimited Edition prints. Structure Decks and Starter Decks are typically printed as 1st Edition, with Unlimited Edition reprints often occurring years later in bundles with errata.
On 1st Edition and Limited Edition cards, the Eye of Anubis Hologram is gold; on Unlimited Edition cards, it is silver. 1st Edition cards also seem to have a darker print coloring than their Unlimited Edition cards.
For Series 3 to 8 cards, the edition text (such as the text "1st Edition") is located under the left side of the card's artwork. From Series 9 onward, for cards without limitation text, the edition text is located to the right of the passcode (leaving a space for the passcode even if the card has none); for cards with limitation text other than Pendulum Monsters, the edition text is located in its previous position (Pendulum Monsters with limitation text do not have edition text).
On the secondary market, 1st Edition prints of cards are typically worth more than their equivalent Unlimited Edition print of the same rarity.