Casing: the outer casing protects the inside parts of the camera. It also prevents light from reaching the film before the shutter opens.
Shutter: a mechanism that opens and closes to expose the film to light for a certain amount of time. This is the click sound when you take a picture, so the shutter only opens for a split second.
Lens: the lens redirect light beams bouncing off an object so that they come together and form a picture. The lens slows light down, causing the light beams to bend from different directions to converge to form an image.
Film: The film, as shown, is a light-sensitive emulsion on a plastic base. When the film is exposed to light when the shutter opens, the light reflects off the surface of the subject, hits the emulsion, and preserves the image.
Flash circuit: this is what causes the flash mechanism. It's purpose is to make a short flash when the shutter releases. It solves the problem of the lack of light for indoor photography.
Gas discharge tube: this is filled with xenon gas: a kind of gas used in neon light or a fluorescent lamp. It's job is to conduct an electrical current by moving electrons by moving one electron to another. When the electrons move, they energize the xenon atoms, causing them to emit visible light photons (the flash).