Complex sentence: The requirement that SU (3) c should be local--that is, that its transformations be allowed to vary with space and time--determines the properties of the strong interaction, in particular the existence of eight gluon types to act as its force carriers.
Split into simpler sentences: The requirement that SU (3) c should be local--that is, that its transformations be allowed to vary with space and time--determines the properties of the strong interaction. In particular, it implies the existence of eight gluon types to act as its force carriers.