A song writer is a person who is responsible for writing lyrics or composing musical compositions for the song. A songwriter is also referred to as a composer in classical music. A song writer who writes the word/lyrics for a song are known as lyricist. Song writing is a very creative work which needs to have a creative thinking.
The pressure from the music industry to create a musical hit often leads to dividing the whole activity into several different parts. A songwriter who writes excellent lyrics can be paired with a songwriter who is capable of creating original melodies. Hence, the work is carried by two different people who together are capable of creating a potentially hit music song. The songwriters are also great musicians sometimes.
They can contribute to the project by playing an instrument, typically the guitar or the piano to hear the melody. With increasing technology, a songwriter can create commercially viable music almost entirely on their laptops. This technological advancement has made the producers/songwriters role much more popular occurrence.