According to the principles of special relativity, the speed of light in a vacuum, denoted by 'c', is constant and the same for all observers, regardless of their relative motion. This means that two light waves, or photons, will always travel at the speed of light relative to any observer.
In the scenario you described, if two light sources are moving in opposite directions relative to an observer, each light wave will be traveling at the speed of light relative to that observer. However, from the perspective of one light source, the other light source will appear to be moving away at a speed equal to the sum of the speeds of the two sources.
It's important to note that while the relative velocities of the light sources can add up, the speed of light itself remains constant in all inertial reference frames. This principle is a fundamental concept in physics and is a cornerstone of Einstein's theory of relativity.