Step 1: Draw the structure clearly: \(CH_3-CH_2-\underset{OH}{CH}-CH_3\). Four carbons in a continuous chain means the root word is but.
Step 2: Presence of a hydroxyl group makes it an alcohol, so the ending becomes -ol: butanol.
Step 3: To fix the position number, number from whichever end gives OH the smaller value. From the right-hand end the carbon bearing OH is carbon number 2.
Step 4: Combine root plus position plus suffix: butan-2-ol. It is a secondary alcohol because the OH-bearing carbon is joined to two other carbons.
\[\boxed{\text{Butan-2-ol}}\]