After April 30, 2013, most Arrival/Departure records will be created electronically upon arrival. Instead of a paper form, the visitor will be provided with an annotated stamp in the foreign passport. If provided a paper form, the admitting CBP Officer generally attaches the I-94 to the visitor's passport and stamps the departure date on the form.
You will receive an I-94 record every time you enter the United States as a non-citizen.