Thread: What is the difference between writing and producing a pop song?

In the mainstream pop music industry today, what is the definition of "writing" a pop song as opposed to "producing" one?
What are the duties of a singer/songwriter and the duties of a song producer?

If you have sources to direct me to, that would be fantastic.

In pop, there are usually several "writers" that claim credit for composing the music and writing lyrics, but many of them didn't really contribute. Sometimes they have a group of professional musicians from music schools like Berklee (prestigious music school in Boston) compose the music based on formulas proven to sell and have the performer write the lyrics with guidance from a team of lyricists. Sometimes, they even have the team just write lyrics based on research on the biggest market for pop music - teenage girls.
Producers are like the coaches for the performers. They oversee the whole finished package. Depending on how musically independent or competent the singer/performer is, the producer might do more or less. S/he might do musical arrangements, tweak the song itself, control mixing, and even marketing sometimes. It also depends on the contract with the label, and how much creative control the performer is allowed.