What is the difference between Du'a of worship and Du'a of supplication?

Supplication (Du'a) is divided into two types: Du'a of 'Ibadah (worship), which is the worship of Allah through various acts of devotion such as prayer (Salat), sacrificing, making vows (Nadhr), and fasting, out of fear and hope, even if it does not contain a specific request. The verse, "Call upon Me; I will respond to you" [Ghafir:60], has been interpreted to mean: worship Me. This is why it is followed by, "Indeed, those who disdain My worship will enter Hell in humiliation" [Ghafir:60]. The second type is Du'a of Mas'alah (request), which is seeking to obtain benefit or repel harm. The two types are intertwined; every Du'a of 'Ibadah necessitates a Du'a of Mas'alah, and every Du'a of Mas'alah includes a Du'a of 'Ibadah, because the One who possesses the power to grant benefit and inflict harm is the only true object of worship.