Alcohols can be a solvent and they are said to be polar if they develop positive and negative charges when the bond between the alkyl group (R) and Hydroxyl group is broken. The Oxygen atom is bonded to the carbon atom in alcohol. The polarity of alcohol depends on the electronegativity difference between carbon and oxygen. Mostly a solvent dissolves a cation easily as compared to an anion.
It is very important to know that hydroxyl is responsible for making the alcohol polar. This is because they form hydrogen bonds with other atoms and thus dissolve in a solvent. We know that like dissolves like. Alcohols are polar so they readily dissolve in polar solvents like water.
As R-OH consists of the OH group we can say that it is half a water molecule. So lower alcohols are miscible with water. However, the alkyl part of the alcohol is hydrophobic and thus makes the hydrocarbyl tail grow longer. This is the reason the polarity and solubility of alcohol decreases.

Note:
In alcohol the –OH side of the molecule is the polar end and the methyl side of the molecule is the nonpolar end. Oxygen is more electronegative than carbon so it attracts more electrons towards itself. Oxygen gains a negative charge and carbon gains a positive charge.