An Intent is an intention to perform an action; in other words, a messaging object you can use to request an action from another app component An Intent is basically a message to say you did or want something to happen. Depending on the intent, apps or the OS might be listening for it and will react accordingly.
Mathematicians consider Descartes of the utmost importance for his discovery of analytic geometry. Up to Descartes's times, geometry, dealing with lines and shapes, and algebra, dealing with numbers, appeared as completely different subsets of mathematics.
For Descartes, however, it was more like the deep night through which the soul must pass on its way to light, the light of reason, and to God as the reason for all things and the source of that light, and then, through God, to the scientific study of the world.