Any material with #-OH# group has Oxygen atoms which has partial electro negativity. These oxygen atoms tend to attract Hydrogen atoms from the adjacent Water and / or alcohol molecules and form partial bonds stabilizing the mixture. This is why alcohols, carboxylic acids, phenols etc dissolve in water. Water is a polar solvent, because it tends to form partially charged particles. While compounds like hexane cannot do so. Polar solvents dissolve polar substances because of the hydrogen bonding interaction as mentioned above.