Let us list some of the factors, which could possibly influence the speed of wave propagation:
(i) nature of the source.
(ii) direction of propagation.
(iii) motion of the source and/or observer.
(iv) wavelength.
(v) intensity of the wave.
On which of these factors, if any, does
(a) the speed of light in vacuum,
(b) the speed of light in a medium (say, glass or water), depend?

Explanation

About speed of light in vacuum :
Speed of light in vacuum is measure experimentally and it is `c=3xx10^(8)m//s` which is now regarded as universa physical constant. It is independent of al the factors mentioned in the statement It is also independent of relative motior between source and observer.
Above points were accomodated as basic postulates in the theory of relativity by Einstein.
(b) (i) Speed of light waves (or sound waves or water waves) does not depend on the type or nature of source. (Its speed depends on the type of medium for its propagation).
(ii) For an isotropic medium, speed of light is same in all the directions (means it does not depend on the direction of propagation).
(iii) Speed of light is independent of relative motion between source and medium but it certainly depends on the relative motion between observer and medium.
(iv) Speed of light in a medium depends on wavelength of light.
(v) Speed of light in a medium is independent of its intensity i.e. whether given monochromatic light beam is dim (less intensity) or bright (more intensity), its speed would be same in a given medium.