The Engineer in Training (EIT) exam, also known as the Engineering Intern (EI) exam, and certification is the first step in acquiring your Professional Engineer (PE) License. Once you take and pass the 8 hour exam, you become an Engineer in Training or Engineering Intern. At this point, you begin to acquire acceptable work experience towards your PE license while working under, in most cases, the supervision of a registered Professional Engineer. The experience required to apply for your PE license is typically a minimum of 4 years but differs from state to state and in some cases dependent on the accreditation of the program you graduated from.
Get to know the Engineer in Training exam a little bit more here