Oh, British Rail Class 108! It is big machine that can move lots of people from one place to another. Think of it like a really big bus that goes on train tracks.
The Class 108 has two parts, called carriages. Imagine a long sausage that is cut in half and you have two pieces - that's what the carriages are like. One part is called the engine and the other is called the trailer. The engine pulls the trailer along the tracks.
Inside the train, there are many seats for people to sit on and windows for them to look out of. You can also find doors that open and close, so people can get on and off the train easily.
The Class 108 was first made a long time ago, in the 1950s. That's when some really clever people called engineers figured out how to build it. Amazingly, the Class 108 can go very fast, up to 70 miles per hour!
Today, the Class 108 is used mostly for short journeys, like from one town to another. People take the train instead of driving their cars because it's much easier and faster. And that's the British Rail Class 108!