# Is the “pocket dimension” a familiar goes into a demiplane or an extradimensional space?

Find familiar allows wizards to send their familiars to a pocket dimension:

As an action, you can temporarily dismiss your familiar. It disappears into a pocket dimension where it awaits your summons.

Is it a demiplane or a extradimensional space?

If it is an extradimensional space, is it attached to the mage? Does it burst a bag of holding if the wizard goes inside?