We want to book Italian train tickets online, on the website, there is "Ticket reference, thet begin within 4 hours from the departure of the train indicated on the receipt / ticket. Change Ticket, change reservation and refunds are not allowed." What does this mean? We mean to take a train from Pisa airport to Siena on 11.18am, does that means that we can take any train within 4 hours from 11.18am? Or We have to arrive Siena in 4 hours time (say if we miss a change at Empoli and take the next one?)
Also, is there same price if we book online or buy at the Pisa Airport's transport station?