How does lubrication reduce friction?

When a lubricant is used between two moving surfaces, its particles get into the uneven parts of the surfaces and make a thin layer of their own between them. As a result the motion actually takes between the layers of lubricating materials, which are relatively smoother. Similarly when we sprinkle powder on a carom board, the power acts as a lubricant. The depressions on the surface of the board and the coins of carom get filled with the powder. This reduces friction between the board, the striker and the coins of the carom.