Electronic data and instructions

System unit is an electronic circuitry which contains different type of components called microprocessor. 

System unit cannot make a directly process such as requests.(computer only recognizes electronic signals.)

Electronic data is the a digital, magnetic stored data which store all kind of stuff such as documents, software and others.Electronic data can be a hard disk , CD ROM, floppy disks ,etc.

data is being represented as two state system or Binary System [0's(off) and 1's(on)]

They are called character encoding

The Binary character encoding consists of;

ASCII also called American standards code for information interchange and is used in microcomputers to represent characters.

EBCDIC also called Extended binary coded decimal Interchange code and used in mainframe computers. These schemes were quite effective but limited.

UNICODE. A popular and most widely used in present day. When internet exploded, it has been founded and is now widely used because of its 16 bits (many number of bits which also allows non English character or special characters to be represented ).

credits: https://prezi.com/i7un_u8key5u/electronic-data-and-instruction/?webgl=0