What are photons and how do they differ from electrons?

The photon is an elementary massless particle representing a quantum of electromagnetic radiation, or light. Albert Einstein was instrumental in developing the concept of the particle nature of light and, in fact, received his Nobel Prize for using the quantum nature of light to explain the photoelectric effect.

Electrons are also elementary particles. Unlike photons, they have mass and charge. Electrons are also sub-atomic particles (along with protons and neutrons).

Why does my son always stare off at lights?

Why does my son always stare off at the light, Lamps, ceiling fixtures, any kind of light fixtures?

I am assuming that your son is an infant. This is more of a question about child psychology than optical phenomena and I am afraid I don't know much about child behavior. Scanning a few websites, though, I see many parents commenting on how their babies love to stare at lights (see this link). I would guess that your son stares at lights because they are fascinating. Bright shiny sources of light are a new experience for him.