Absolute alcohol is nothing but pure alcohol, free from any impurities.
In order to prevent the misuse of ethanol in industries, it is made unfit for drinking by adding poisonous substances to it like methanol. Dyes are also added to colour the alcohol blue so that it can be identified easily. This is called denatured alcohol.
Rectified sprit : is 95% alcohol by volume.In other words, it is highly concentrated alcohol.
It is used in medicinal industry and production of liqueurs.
It is also used as a household cleaner.