There were two types of streamlined steam locomotives. Those that had a streamlined cover placed over an older locomotive, and those that were actually built as streamlined locomotives. The streamliners were pretty amazing to look at, especially the American ones which looked like something out of Flash Gordon.

Well of course they are 'real' steam engines! On the really high-speed machines, like the famous LNER Gresley A-4s, they went fast enough for the streamlining to make a difference in reducing air resistance. Others were streamlined to make them appear modern and to look as if they were fast. From the same stable were the two Gresley B-17 class 4-6-0s - streamlined in the same way as the A-4s, but only for appearance's sake. Personally I was impressed by O.V.S. Bullied's 'Air-smoothed' pacifics for the Southern Railway. In this case, the streamlined casing was intended to both reduce weight and make the engines easier to keep clean, and well as blending visually with the carriages.

Yeah they're the same. The streamlining does not change its power source.

Yes, of course they are 'real' steam engines!

The streamlined cowling had to be taken off for maintenance and, eventually, after the novelty had worn off, they often didn't bother to put it back on.

Of course they are. Some of them were rolling works of art in my opinion. Underneath the artistry beat the same heart as any other steam locomotive. I got to be the pilot engineer on the UP's 844 steam engine. It's the exact same basic layout (they were built by different builders but are very similar) as Southern Pacific's old Daylight which was a streamlined train that has been called one of the most beautiful trains in the world.https://www.google.com/search?q=Southern+Pacific%2...

they were pretty but really did;nt serve the purpose for making the train faster

Of course, why shoud they not be?