What is the Throne of Allah in Islam?

What the Quran says

The Throne is mentioned again and again, often to show Allah's power and greatness. One short verse sums up the belief:

Other verses call Allah "Lord of the Great Throne" (Quran 9:129), say His Throne was over the water before the heavens and earth were created (Quran 11:7), and tell us that on the Day of Judgement eight angels will carry it (Quran 69:17).

What the hadith add

• Above Paradise: the Prophet ﷺ said the highest level, al-Firdaws, is in the middle and top of Jannah, and above it is the Throne of the Most Merciful, and from al-Firdaws the rivers of Paradise flow (Sahih al-Bukhari 2790). See What are the levels of Jannah?
• Before creation: Allah wrote the decrees of creation fifty thousand years before creating the heavens and earth, while His Throne was over the water (Sahih Muslim 2653).
• Carried by angels: great angels carry it and glorify Allah. See Do Muslims believe in angels?

Throne ('Arsh) vs Footstool (Kursi)

Ayat al-Kursi says Allah's Kursi "extends over the heavens and the earth" (Quran 2:255). Many early scholars, reporting from Ibn Abbas, said the Kursi is distinct from the Throne and far smaller than it, though still vast beyond imagination. See What is Ayat al-Kursi and when do I recite it?

How do Muslims understand "rising over" the Throne?

Allah doesn't need the Throne; it is His creation and depends on Him. Imam Malik's famous answer is often quoted: the rising is known, how it happens is unknown, believing in it is required, and asking how is an innovation. Sunni scholars generally take one of two approaches: affirming it as Allah described Himself without asking "how" (the way of many early scholars), or affirming it while understanding it in a way that rules out any physical resemblance (a common Ash'ari approach). Both reject likening Allah to anything in creation.