Meaning
A computer mouse with two buttons and often a scroll wheel, sometimes drawn with its cable. It stands for clicking, pointing and finding your way around a screen.
People use it for fast clicking in online sales, gaming aim or telling someone where to click: “Midnight flash sale, finger already on the 🖱️.” Do not confuse it with 🐁 the animal; this one is purely the gadget, often paired with ⌨️ or 🖥️.