There are several traditional methods for creating starters for breads. All of these starters are easy to prepare.
A starter usually consists of a simple mixture of wheat flour, water, and a leavening agent (typically yeast or a sourdough culture). After mixing it is allowed to ferment for a period of time, and then is added to bread dough as a substitute for, or in addition to more yeast. So preferments are critical for best tasting bread – You can call it a starter, biga, poolish, preferment, or sponge – they all do sort of the same job and only really differ by water content.

Biga and poolish are terms for preferments used in Italian and French baking, respectively, for sponges made with domestic baker’s yeast. Poolish is a fairly wet sponge (typically made with a onepartflourtoonepartwater ratio by weight), while biga is usually drier. Bigas can be held longer at their peak than wetter sponges, while a poolish is one known technique to increase a dough’s

The primary difference between making bread with a starter and making bread with the direct or straight yeast method is that starter breads require much more time to prepare, but the flavor and texture of the bread is almost impossible to achieve with other leavening methods. Bread made with starters like poolish and biga also tends to keep better, compared to bread made from straight doughs.