The human immunodeficiency virus (HIV) is a lentivirus (a subgroup of retrovirus) that causes HIV infection and acquired immunodeficiency syndrome (AIDS).AIDS is a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive.he human immunodeficiency virus (HIV) is a lentivirus (a subgroup of retrovirus) that causes HIV infection and acquired immunodeficiency syndrome (AIDS).
The definition of optimal is the most favorable. An example of optimal used as an adjective is in the phrase optimal score, which means the highest score someone can get on a game. most favorable or desirable; best; optimum. Origin of optimal.
1 Represents the (median) ânormalâ price in the market or the price of a market leader. 2  The optimal price point (OPP). 3  The âsweet spotâ where the number of people who find the price acceptable is maximized, and resistance to price changes is minimized.