What type of expansion slot was primarily used for graphics cards before being replaced by PCI Express?

The AGP (Accelerated Graphics Port) slot was specifically designed to enhance the performance of graphics cards before the rise of PCI Express (PCIe). It was introduced in the late 1990s and provided a dedicated point-to-point connection between the graphics card and the motherboard, which allowed for faster communication and more bandwidth compared to previous technologies like PCI. The AGP slot helped to improve graphic rendering and overall visual performance in applications and gaming during its time. While PCI slots were used for various peripherals, they were not optimized for the demands of graphics processing in the same way that AGP was. PCI Express eventually superseded AGP by offering even greater speeds and flexibility, but AGP was the dominant interface for graphics cards prior to that transition.