What physical size of hard drive are installed in laptops?

Laptops typically use 2.5-inch hard drives, which are smaller than the 3.5-inch drives commonly found in desktop computers. Additionally, many modern laptops now utilize solid-state drives (SSDs), which can come in various form factors, including 2.5-inch, M.2, and PCIe NVMe drives. The choice of drive size and type often depends on the laptop's design and intended use.