Sell is a verb and sale is a noun:

I'm going to sell my car and buy a new one.

She's selling bottles of water at the football game.

Yesterday I sold all of my old college textbooks on the internet.

The bookstore is having a Christmas sale - everything is 20% off.

(20% off = 20% discount)

The sales of our new product are slowly increasing.

This watch is normally $100, but it's on sale for $70.

(on sale = there is a discount)

There's also a pronunciation difference between sale and sell.

What to Eat in Orissa

Mitha Dahi

Mitha Dahi or Mishti doi is a fermented sweet dahi or sweet yogurt. This type of yogurt is common in the states of West Bengal and Odisha in India, and in Bangladesh.It is made with milk and sugar, while also using yogurt and curd. Mitha Dahi is a popular dessert in the states of West Bengal, Odisha and Bangladesh. It is prepared by boiling milk until it is slightly thickened, sweetening it with sugar, either guda/gura (brown sugar) or khajuri guda/gura (date molasses), and allowing the milk to ferment overnight. Earthenware is always used as the container for making Mitha Dahi because the gradual evaporation of water through its porous walls not only further thickens the yoghurt, but also produces the right temperature for the growth of the culture. Very often the yoghurt is delicately seasoned with a pinch of elaichi (cardamom) for fragrance. Baked yogurt is a similar preparation in the west.