The stoning sequence differs between the Day of Sacrifice (10th) and the Days of Tashreeq (11th-13th). On the 10th of Dhul Hijjah, only one pillar is stoned: جمرات al-Aqabah (also called al-Kubra — the largest pillar, located nearest to مکہ مکرمہ). You throw 7 pebbles at it, saying 'Allahu Akbar' with each throw.
On the 11th, 12th, and 13th of Dhul Hijjah, all three pillars are stoned in a specific order, starting from the one farthest from مکہ مکرمہ and moving toward مکہ مکرمہ: (1) جمرات al-Sughra (the smallest, farthest from مکہ مکرمہ) — 7 pebbles; (2) جمرات al-Wusta (the middle pillar) — 7 pebbles; (3) جمرات al-Aqabah / al-Kubra (the largest, nearest to مکہ مکرمہ) — 7 pebbles. This order is wajib (واجب) جمہور علماء کے مطابق.
The Sunnah after stoning al-Sughra is to move to the side, face the Qiblah, raise your hands, and make a lengthy دعا. Similarly after al-Wusta — stand, face the Qiblah, and make دعا. However, after stoning al-Aqabah (the final pillar), you do NOT stand for دعا — you simply leave the area. This follows the exact practice of نبی کریم (صلی اللہ علیہ وسلم). The modern جمرات bridge is a multi-level structure designed to ease crowding — you may stone from any level, and the pillars are now wall-shaped (not actual pillars) with a basin to catch the pebbles.