What is the difference between the prayer of asking (Du'a al-Mas'alah) and the prayer of worship (Du'a al-Ibadah)?

The word "Du'a" (supplication/prayer) is used for two meanings: Du'a of request (seeking benefit or averting harm), and Du'a of worship (worshipping Allah through any type of acts of worship). In the Holy Qur'an, the word "Du'a" mostly encompasses both meanings together, as they are intertwined: the one who requests is a worshipper, and the worshipper seeks reward. Ibn Taymiyyah clarified that Qur'anic verses dealing with Du'a often include both types, and that one may be more explicitly intended in some verses. He cited verses such as (إادْعُوا رَبَّكُمْ تَضَرُّعًا وَخُفْيَةً) "Call upon your Lord humbly and privately" and (وَقَالَ رَبُّكُمُ ادْعُونِي أَسْتَجِبْ لَكُمْ) "And your Lord says, 'Call upon Me; I will respond to you'", which he interpreted as encompassing both Du'a of worship and Du'a of request. He affirmed that Du'a is worship, as stated in the Hadith.