Definition:
1) The present perfect continuous is used, like the present perfect simple, to express an action which begins in the past and continues into the present moment. For example, My parents have been travelling since early this morning.
2) BOTH the present perfect and present perfect can be used when expressing the duration of an activity that begins in the past and continues into the present. We tend to use the present perfect continuous to describe the duration of a current activity happening at the moment. For example, I've been reading this book since 10 this morning.
On the other hand, the present perfect is used to describe states or more general activity. For example, Jack has lived in California most of his life.
