what are rabi,khaif and zaid crops

Kharif Crops : The Kharif crop is the summer crop or monsoon crop in India.
Sown in : beginning of the first rains in July
Harvested : during the rainy (monsoon) season , between April and October. Major Kharif crops of India include rice, Millets (Bajra and Jowar), Maize, Mung bean, Groundnut, Red Chillies, Cotton, Soyabean, Sugarcane, Turmeric,Urad bean etc.

Rabi Crops: The Rabi crop is the spring harvest or winter crop in India.
Sown in: Winter ( Last of October)
Harvested in : Spring (March, April) Major Rabi crops in India include Wheat, Barley, Mustard, Gram, Sesame, Peas, Sunflower, Coriander, Tomato, Onion, Potato, Oat etc.

Zaid Crop: The crops grown on irrigated lands which do not have to wait for monsoons, in the short duration between Rabi and Kharif crop. Major Zaid crops in India are Watermelon, Muskmelon, , bitter gourd, pumpkin, cucumber etc.