I am trying to understand the difference between these two terms. From what I understand SOA has two types of implementation namely SOAP and REST, and the method of architecture that uses REST is called ROA. This means ROA comes under the category of SOA. There are some other places which say in contradictory way.
Any help will be appreciated, rectify me if i'm wrong.
SOA is actually fairly old, and predates much of the internet. It is a pattern of creating software with more than one potential consumer. There are MANY implementations of SOA, far beyond SOAP and REST.
A ROA is just a more specific term for a SOA. It is like talking about elephants and mammals. Not all mammals are elephants, but all elephants are mammals. Not all SOAs are ROAs, but all ROAs are SOAs.
I'd be curious about a any contradiction to this. I don't think you could build a ROA that is not also a SOA. The closest I could think of is if you did not implement a networking layer, and only invoked resources in-memory. That would be dumb, but you could theoretically do it.
