Generally, when you are preapproved for a credit card, it means that a preliminary review of your credit record by the card company indicates you may meet the criteria it seeks in a customer. You are not absolutely guaranteed to receive a card—or the credit limit, interest rate, or other terms featured in the promotion.
You will only receive the card if you apply and if you meet other criteria that the card company has established. These other criteria, including making sure that your credit record has not deteriorated since you were selected for the offer, will determine whether you get the card, and if you do, the credit limit, interest rate, and other terms for the card.
You should read the promotion very carefully before applying.