An "itinerary" is a document which shows details about someone's travel.
One kind of itinerary is the document that you receive when you book a trip on an airline. The itinerary tells you when each flight will depart and arrive.
Another kind of itinerary is a detailed plan that some people create for themselves when they visit a new city. They decide in advance what they're going to do each day. For example, if you travel to New York City you might create an itinerary like this:
- Saturday, 9 a.m: Breakfast
- Saturday, 10 a.m: Visit the Statue of Liberty
- Saturday, 12 p.m: Pizza at Grimaldi's in Brooklyn
- Saturday, 2pm: Museum of Modern Art