1 Visa - Digits two through six are the bank number, digits seven through 12 or seven through 15 are the account number and digit 13 or 16 is a check digit.  MasterCard - Digits two and three, two through four, two through five or two through six are the bank number (depending on whether digit two is a 1, 2, 3 or other). The digits after the bank number up through digit 15 are the account number, and digit 16 is a check digit.
AIDS is the acronym for acquired immunodeficiency syndrome. 1  It is the stage of HIV infection where a person's immune system is fully compromised, leaving the body open to a wide range of potentially deadly diseases known as opportunistic infections.
HIV is the virus that causes AIDS. It is spread mainly through blood and sexual contact. You can have HIV and feel healthy. Over many years, however, the virus can wear down your body's immune system, making it hard for your body to fight off dangerous infections. Having HIV also can increase your risk of getting certain cancers.