It stands for Central Processing Unit and it’s also called the brain of a device either it’s a mobile or a computer. When we enter a command in the mobile phone or ask the device to perform a task, it is run by the CPU inside the hardware of the cell phone and the speed of the task completion depends on the speed and type of CPU. A decade ago, mobile phones were used to include 200Htz or up to 500Htz of processor where these days, including a 2.5MHz processor in a cell phone is very common.
It stands for Graphics Processing Unit and it’s a specially designed CPU only to process the images or graphics on the cell phone. With higher GPU, the user interface is made easier, quicker, faster and more efficient along with providing the sharpest and clearest images on the display of the cell phone with every last detail available.