Akshat Kothyari

The comparison is not right. When you say digital keyboard, it is competitor is the analog keyboard. The different between them is the procedure of creating different sounds. In digital Keyboards you'll find pre made sounds like organ, piano, etc. While in analog keyboard you would have to create the sound from scratc which in itself is a very complicated procedure to explain here. And since the term normal keyboard is very subjective (could be both digital or analog) this question cannot be answered. I'm guessing that you want to compare and electronic keyboard with acoustic piano. Keyboard is where you can find different sounds and in acoustic piano there is only one. Other differences include the size, weight, action (which is the force exerted by the keys when you press them), etc.

To play a song perfectly there are various stages 1. Pick up the notes of the song. This can be done in three ways. First is you can use sheet music in which you would be provided with the staff notations. Second is you can ear pick the song, that is you can listen to song and pick up the right notes. Third is you can always use online videos or tabs to check the notes (not preferable for a good musician). 2. Once you know the notes you need to practice them. First do it at a slow tempo. For keyboardists and pianist you can always practice individual hands first and then use both of them together. Then keep increasing the tempo as you master the slower one. 3. Once you are confident enough practice with the original song. That is listen to the song and play with it. If you are not lagging or speeding up anywhere and playing all the notes right then you have perfected the song.