Have you ever wondered that how things like inline skate wheels and electronic motors spin so smoothly and quitely ?
The answer can be found in a little machine element called bearing.
The bearing makes many of the machines working possible which we use everyday.
So, A bearing is simply a machine which is used to support the shaft transmitting power and to reduce frictional losses between machine elements.
As we all know if we have to transmit power to a long distance then we need a long shaft.
In that case we use a bearing to support that shaft to prevent its bending due to its own weight and also to reduce frictional losses.