This is the processor, otherwise known as a CPU. Some people crudely refer to it as the “Brain” or “Heart” of a computer or robot. There is a grain of truth there, in that it is the main computing element of any system.
At its most basic, it is a unit which can process and run instructions in a system. The instructions are a program, and the kinds of program could be anything from a simple clock to some of the most sophisticated games and software available. The instructions are executed in a sequence by a core of the processor.
Through advanced programming techniques, a single CPU core can divide their time among many programs, and give the appearance of running many programs simultaneously - this is known as multi-tasking. A single running program (also known as a process) may have multiple tasks, known as threads. Multi Tasking techniques consist of a task being able to run a block of code, followed by an instruction to yield back to the task manager so it can store all its state and give some run time to another task. Many modern systems now have many cores running code simultaneously, but have to be careful around resource access like memory and input output devices to ensure consistency of data.
The term MicroProcessor came about from the fact that at one time, old CPU’s took up whole rooms, or at least a five foot by two foot by six foot module (which did not include storage, hard disks or displays). They were then massively miniaturised to the size now, which is most definitely comparatively micro.
Old CPU’s and Computers
If anyone has had the privilege of seeing such a system, such as the one at the Bank of England registrars department, they would often have a cluster of 2 rows of 10 5 foot cabinets, which were the processing cores, surrounded by walls of tape loop machines, sets of Hard Disk Drives powered by motors the size of motorbike engines, and had a room full of chain printers (where the characters are embossed on dies which are mounted on a constantly spinning chains) for backups. The whole facility was about half the size of a gymnasium.
In modern terms, a mobile phone probably comes with more processing power and storage than these kinds of systems did, a mark of how fast the technology has moved in 30/40 years.