Key Difference: A rail is a set of two parallel rows of long pieces of steel or iron.  A train is a mode of transportation that runs on these laid tracks of rails and is generally used for long distances; a train usually runs outside city limits.

The difference between rail and train seems to be confusing as rail and trains are used in same context. However the literal meaning of both is different. Rail is defined as the track generally made by setting two parallel rows of steel and iron and this track is used by trains to move from one place to the other. It can also be defined by saying that a train is a mode of transportation and it runs on these specially laid tracks of iron rails known as railway track (or rail). Train is generally used for long distances; a train usually runs outside city limits.  So, we can simplify by saying that rail is the track used by trains or trains run with placing their wheels on these rails. A train is also a form of rail transport that consists of series of coaches coupled together and is drawn by a locomotive. It is used to transport freight or passengers from one place to another.  Train is a locomotive with an engine and coaches and rails provide the tracks in which these trains  move.  Railways department therefore, not only takes care of the trains but as suggested by its name, is also responsible of maintenance of rails or railway tracks.

A tram may also run on railway tracks. Historically steam powered trains were used but now diesel and electric 

sources are being harnessed. A freight train is specifically used to transport goods or materials. High-speed rails are growing fast as they can run over 200 km/h of speed. Monorails have also been developed. Monorail is based on single rail.

A rail consists of two parallel steel or iron rails that are set at fixed distance to each other, called as gauge. The rails are connected to each other by railroad ties, can be of concrete or wood. Most of the rail segments are welded for a smooth ride. The rails are little inclined towards each other, typically on a slope of 1 in 20, and the rims of the train wheels are placed in similar angles. Due to this reason, the train is guided along the track. Trains are very effective modes of transportation for any city or country as they are wide spread throughout in the world. Railway department takes care of all the necessary work related to trains and rails. The technology has been advancing with each coming day and therefore now with monorails we can expect some other higher advanced technology for the trains.

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