Question

explain concave and convex mirror and lens?

Answer 1

convex lenses can be used to get magnified or larger images of objects.as it shows small images,it can be used as spectacles for short sightedness (myophia).it can also be used in flashlights, peepholes, binoculars, telescopes, and in photography.it is also kept in curves of road to get a better view of the coming vehicles which cannot be seen by the other driver.it can reduce accidents.
concave lens can be used as reflecting surfaces in headlights of cars, in telescopes, in satellite dishes, as shaving mirrors, in torch and etcconcave mirror 
has a curved in shape or structure.it goes in like a cave.
they are thinner in middle
they passing in rays spread out.i.e they diverge.
image formed is real and also virtual.
convex mirror
it has a bulging out structure
they are thicker in the middle
it will not let the rays diverge instead they converge.
the image formed is always virtual