Intensive reading or listening is when we read closely to find detailed information and reach a thorough understanding of a text.
Extensive reading and listening refers to approaching longer texts, which are read more rapidly for a more general global understanding.
Extensive reading in language learning is when students read texts for pleasure and
for developing their general reading skills; they are not required to do tasks.
Classroom reading and listening lessons usually involve intensive
reading/listening, which means reading closely to complete specific
tasks.
Extensive reading and listening are probably the best ways of improving comprehension and expanding vocabulary. It is useful for teachers to find ways of encouraging students to read and listen extensively as well as intensively.