General term for permanent or non-permanent

A general term (which doesn't imply either side of the scale) is duration:

[Merriam-Webster]
2 : the time during which something exists or lasts
// were there for the duration of the concert

An example sentence more suited to the question is the following:

Does it have a temporary or permanent duration?

In a form, duration could also be filled in with a particular time period.