What is pinhole cameta give it constraction and working?

If you just do a search for this phrase ----> "how to make a pinhole camera" <----- you'll have all the answers and information you could ever need. Basically it's a box with a pin hole at one end and a sheet of light reactive paper inside the box opposite the hole. Cover the hole, expose the film by removing the cover and then recover the hole. Use a dark room when you put the film in the box and when you take it out to develop the film.