Brain of the computer system is called​

central processing unit in short form CPU :)

The Central Processing Unit(CPU)

Explanation:

The CPU is the brain of a computer, containing all the circuitry needed to process input, store data, and output results.

solution:

the auto-correct option of the auto-correct tool enables you to add and delete words that do not follow abbreviation rules because:

it is a feature that allows outlook to correct common spelling and typing errors and to replace characters with symbols. we can also can use auto-correct as a shortcut, which means we can type a small string of characters and have those characters replaced by a longer string.

english /