Is There a Difference Between Empire a and Empire B?

There are two very similar computer games from the 19 seventies named empire a. According to everything i've been able to find out in my very limited skimming around the inner net, which i pretend to call research, these were developed independently. Different people on different systems created different versions as the 72 verson is the earlier of the two. The one that i think maybe more people are familiar with today is the latter of the two, made in the later seventies and then imported to everything under the sun,. Still available for for download free, and which i still play. It is very sieve like.