When you want to access the data/value in the memory that the pointer points to - the contents of the address with that numerical index - then you dereference the pointer.

Why do we need to dereference a pointer?

Dereference a pointer is used because of the following reasons: It can be used to access or manipulate the data stored at the memory location, which is pointed by the pointer. Any operation applied to the dereferenced pointer will directly affect the value of the variable that it points to.

What is a pointer dereference?

Dereferencing is used to access or manipulate data contained in memory location pointed to by a pointer. *(asterisk) is used with pointer variable when dereferencing the pointer variable, it refers to variable being pointed, so this is called dereferencing of pointers.