Very basic optics questions: 1. So light is a type of radiation, due to which we see objects. Some objects, like a candle, are luminous and we can see them without another light source. Some other objects are non-luminous, and we need a light source to have light reflected upon them. How does this work? Does the light source release light rays which are reflected from the object and enter our eyes? When they enter our eyes, how do we see the object and know where it is? Is the object located from where the rays originate/intersect? 2. Can someone explain real images as to what it means with respect to being displayed on a paper screen? 3. Are real/virtual images distinguished in the sense that if the extrapolated rays behind mirror intersect, then it's virtual and if they intersect in front of the mirror it's real? Why is that? 5. In real/virtual images, why are images located where the reflected rays intersect/originate? Not homework, just need my basic concepts clarified. Thanks.