According to Sam Newman (author of some books on the subject) the difference between them is in the communication protocol, in the implementation, flexibility for changing technologies, independent evolution of each part of the software, ease in deployment, modeling aimed at specific business contexts.
Given that some of the features cited are also advantages of microservice-oriented architecture.
While SOA is generally a style of architecture that has a larger and more integrative corporate focus.
In short: The difference between SOA and Microservices is basically the scope.
SOA is more focused on the corporate scope, while microservices is more application-oriented.
The services are always implemented individually in SOA, this is the main advantage of this architecture actually. Microservice is relatively new. "The term 'Microservice Architecture (Microservice Architecture)' has emerged in recent years to describe a specific way of developing software as service suites with independent deploy." (https:/martinfowler.com/articles/microservices.htmlfree translation)
– LeonanCarvalho