Many train services offer either 'Standard', or 'First' Class' tickets (and therefore seating). First Class is much more expensive than 'Standard Class', which most people find perfectly comfortable. It is advisable to book a seat in advance on long distance journeys, especially if you plan to travel on a Friday.
Train services are operated by a variety of different companies. Some companies offer special deals, especially if booked in advance, on certain routes (usually longer distance routes). For timetables and fares, see the National Rail website.
Students can get the train from Gatwick or Heathrow to London and then get a connecting train from Paddington to Swansea. For train times and prices please see the National Rail website - Please remember to read the terms and conditions.
Please make sure you book your train ticket before travelling to Swansea.