They`re basically the same - it`s a choice by the company which naming to use, I presume.
And... they all taste different. Every maker (that actually makes the stuff and not mixes things to make a pseudo "soy" sauce) has their own special blend and process. Even Kikkoman sold outside Japan tastes different than the same brand sold inside Japan.
In other words - try a number of brands and find the type you like the best. We swear by
Mataichi.