No.

Interrail/eurail is the official company that oversees and sells tourist pass rail products.

It is run as part or at least on behalf of the group representing European rail operators.

Rail Europe and any number of other similar outfits are essentially independent travel agencies that resell products from various sources including interrail and tickets from rail operators.

These range from legitimate companies that sell official products to out and out scammers.

Rail Europe are also the agency who sells interrail/eurail passes on behalf of the UK rail companies through the officially endorsed myinterrail.co.uk website.

RailEUR has a history of being set up under another name (LoCo2) to make rail-bookings simpler online-this is a major stumbleblock for now to prevent many people from the so wished by the greens and a girl named Gretha fra Sverige from flying to training. It has since been swallowed up by I think an offspring of SNCF (french national state and very burocratic railways) but as such for selling normal tickets is reliable and qute OK.

To AVOid are those that often spring up first in google-searches: railninja and rome2rio.

But NONE of these can do what people on this forum want: RES only as they already have the ´ticket´/pass for their travels as such.

RailEurope is a Travelagency that is now in the hands of French Rail (They were quite good for reservations but as SNCF has no taken over the reservationservice of RailEurope is gone worse to non existend )

Eurail B.V. based in Utrecht NL.  Is the dutch company behind Interrail and Eurailpasses agencies like RailEurope are Reseller Raileurope (French Rail) B-Europe (Belgian Rail) and many many more.

Eurail offer a own reservation service but charges for that ontop of the reservation costs a Service fee. Many reservations can be done online via the websites of the National railcompanies in Europe there is a topic called “How to get Reservations” in this Community with manuals and explanations