I think what your asking is what the heart and soul of a comp is and im pretty sure its a Motherboard ☺
You can by either for computer or iPhone. For computer you can go like this <3 for iPhone u can buy an aft called emoji free and then get this 
The heart of a computer is the central processing unit (CPU). This device contains all the circuitry that the computer need to manipulate data and execute instructions. Motherboard is like that body of the computer, and the CPU is like the brain of the computer.
because the system unit contains everthing that helps the computer to work
the heart of a computer is the proccesor
like this:
put a < then put a 3 it should look like this <3 if you look at it side ways it looks like a love heart +_+
It's called heartburn because the burning sensation is in the general area of the heart. It feels like your heart is burning!
Monitor.
you can do <3 if u turn sideways it kinda looks like a heart
You can do it in 2 ways. 1: Click ALT and 3 and it should come out like this: (only one heart) 2: or you can do this: <3 <3 (but i like the first one better)
The device where the operating system is stored on a computer is called the CPU. CPU stands for Central Processing Unit and is the heart of the computer.
It's called golden section