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.
Human immunodeficiency virus (HIV) causes HIV infection and AIDS. The virus attacks the immune system. As the immune system weakens, the body is vulnerable to life-threatening infections and cancers. Once a person has the virus, it stays inside the body for life.