In Illinois, depositions come in two varieties, discovery and evidence. The lawyer who sends the deposition notice makes the selection and states it on the notice.
What if the notice doesn't specifically state the type of deposition? When this happens, the deposition is a discovery deposition, as explained in Rule 202--
The notice, order, or stipulation to take a deposition shall specify whether the deposition is to be a discovery deposition or an evidence deposition. In the absence of specification a deposition is a discovery deposition only.