Does Light Have Inertia?

Inertial mass is like the resistance of an object to changing its velocity. And photons can't change their velocity, right? They always travel at the speed of light. So inertia when it comes to photons is very confusing. I think there's a few different concepts here. There's momentum, which light definitely carries. But inertia here, we're talking about inertial mass and photons definitely don't have any inertial mass. All right. Some particles in the universe seem to have inertial masses. It's sort of related to Einstein theories about gravity too,. That's right. The proton has a lot of inertial mass because of the energy in it.