The central processing unit (CPU) is a device that interprets and runs the commands that you give to the computer. It is the control unit of a computer. The CPU is also referred to as the processor.
Memory is where information is stored and retrieved by the CPU. There are two main types of memory.
· Random Access Memory (RAM): It is the main memory and allows you to temporarily store commands and data. The CPU reads data and commands from RAM to perform specific tasks. RAM is volatile, which means it is available only while the computer is turned on. The contents of RAM must be copied to a storage device if you want to save the data in the RAM.
· Read Only Memory (ROM): It is the memory that retains its contents even after the computer is turned off. ROM is nonvolatile, or permanent, memory that is commonly used to store commands, such as the commands that check whether everything is working properly.
