The secured credit card term means that by placing some of your money as a security deposit or collateral a credit card company will issue you with an equivelent amount as credit limit on their card. An example of this is if you place $500.00 up as a deposit the credit card company will give you usually $500.00 as a credit limit.
This establishes a credit reference on the bureaus and allows you to purchase goods with you card and pay as per the card holder agreement. Once an individual has demonstrated a responsible use of the card then they can apply to have the security amount reduced or returned while maintaining the credit limit.
Make sure that if you obtain a secured credit card that the company will pay you interest on your deposit and that it is not just a fee.