Stack Overflow has separated itself as one of the best places for developers to go when they have a coding question that needs answering, and 'Stack Overflow for Teams' is a new division of that service that makes it safer for developers working in large organizations. The system effectively creates a private Stack Overflow page for individual enterprises, so developers can freely ask any question and look up any issue.
Many questions that need answering in relation to errors and other technical issues can be asked to the public, but certain companies don't have that luxury. Asking a question might necessitate giving away proprietary code, and that's obviously unacceptable. Stack Overflow for Teams might not have the breadth of the public facing site, but it creates a space where there's no hesitation in sharing that private code.