An Indian kitchen may keep three or four rices at once, each bought for a particular dish. The sorting principle is starch behavior rather than quality or price.
Two starches decide how a grain cooks
Rice starch is a mix of amylose and amylopectin, and the ratio between them determines whether cooked grains stay separate or cling together.
High-amylose grains cook dry and distinct, which suits dishes where each grain should be visible and coated rather than merged into a mass.
Grains higher in amylopectin swell and stick, which is what makes them right for dishes eaten in handfuls or in soft, soupy preparations.
Aging changes a grain before it is sold
Freshly harvested rice holds more moisture and cooks softer and stickier. Stored for a year or more, the same rice absorbs more water and cooks firmer and longer.
This is why aged long-grain rice commands a premium for layered dishes, since grains that elongate without breaking are the entire visual point.
New-crop rice is not inferior, only different, and it is preferred where softness is wanted, so the two are genuinely separate products rather than grades of one.
Parboiling restructures the grain
Parboiled rice is soaked, steamed and dried in the husk before milling, which gelatinizes the starch and drives some nutrients from the bran into the grain.
The resulting grain is harder, cooks slower and stays firm and separate, which suits daily eating in regions where rice is served at every meal.
It also holds up in fermented batters and in reheating, so it dominates in the south while the north leans on raw milled rice.
Short and broken grains have their own uses
Short-grain rices are chosen for milk puddings and for soft, watery breakfast preparations, where the collapse of the grain is what gives the dish its texture.
Broken rice, once a byproduct, is used deliberately where a thick, porridge-like body is wanted and the shape of the grain does not matter.
Flattened and puffed rices belong to the same family of uses, being processed forms chosen for how they absorb liquid rather than for how they cook in a pot.
Buying with the dish in mind
American supermarkets increasingly stock aged long-grain rice, but the label rarely states the aging, so the price and the importer are the practical signals.
Indian groceries sell parboiled and short-grain varieties under regional names, and asking which one a dish takes is more reliable than translating the packaging.
Rinsing is the one step that applies across all of them, since surface starch left on the grain gums the finished rice whatever variety went into the pot.