As for service outsourcing, you can regard it as an industry, just like auto parts outsourcing, which is simply the service supply and demand of enterprises.
The so-called software outsourcing means that some software companies in developed countries hand over some of their non-core software projects to companies in countries with relatively low human resource costs for development, so as to reduce the cost of software development.
As we all know, 70% of the cost of software development is the cost of human resources, so reducing the cost of human resources will effectively reduce the cost of software development.