What is the difference between the words inactivate vs deactivate?

Answer 1

Inactive is a state of being. Deactivated is the result of an action. To deactivate (verb) something, it must first have been activated; you render it inactive (adj.).

Example 1: A security badge is activated, and subsequently may be deactivated. A security badge that has never been activated cannot be deactivated.

Example 2: A volcano may be dormant and therefore is considered inactive or not active. However, because it was never activated, it cannot be deactivated.

It's preferable not to use the verb 'inactivate' or 'inactivated.' Use the verb 'deactivate' or one of its forms to describe an action; use the adjective 'inactive' or 'deactivated' to describe a thing.

The opposite also applies: 'activate' or one of its forms indicates an action, and 'active' refers to a state of being.

Comment:

The question is asking about 'inactivate' not 'inactive', compared to 'deactivate'. There is no difference between inactivate and deactivate, except the context it is used in. Inactivate is usually used in a scientific context, particularly with regard to genetics. Deactivate is used outside of the scientific context to refer to the same concept, to render something no longer active. Both the prefixes, 'de-' and 'in-', are used to indicate privation, and so are hardly distinguishable in some cases.

Example 3: Lyonisation is a process that can inactivate X chromosomes when more than one is present in the cell.

Example 4: When students wish to study for their exams they will often choose to deactivate their Facebook accounts.