First Great Western services. BritRail

It's one of the companies running train lines in the UK. The railways there are privatized. You can see all of them through nationalrail.co.uk.

OK So how would I book that rate?
For example I did a search on London > Bath SPA and for May 20 at 1030. I get five different 2nd class ticket options from US$43 to US$156. If this is the same train #1030 why would anyone choose other than the lowest fare?

The different fares give you different levels of flexibility. The cheapest fare means that you absolutely have to use that train and if you miss it you need to buy a new ticket. The most expensive one will let you travel on any train, and the others will be somewhere in between.

There are different ticket types. The cheapest are 'Advance' fares, which can only be used on the specific train for which they are booked and cannot be refunded. There are a couple of different flavours of Off-peak ticket, valid after peak commuting time (which would certainly include the 10.30), and 'Anytime' fares, which as the name suggests you can use on any train.

Thanks. Think I now understand. Will be sure to look at the "fine print" before selecting the ticket.

There will also be a difference in price between First Class with its large 2+1 seating and different levels of food and catering, and Standard Class where most people sit in 2+2 or 2+3 seating. I think that First Great Western has all 2+2 seating on that run but I may be wrong. It is called First Great Western. Don't know about the Services part, although trains are often called services. So service = train in this case. There is no domestic use of the term BritRail any longer. The trains are all referred to by their respective operators. BritRail is used overseas as collective marketing, and to sell BritRail passes which are used by foreigners for various parts of the country and on specific operators.