When these posts on the site say 'cold pitch', what does that mean? Contextually I am picturing someone literally writing up a contact off the publisher website

When these posts on the site say 'cold pitch', what does that mean? Contextually I am picturing someone literally writing up a contact off the publisher website, saying 'Hey would you pay me to write this?' and they get back a 'yup, send it in and we'll pay you something'. I have no awareness of this but I am fascinated by it.