ASCII
stands for American Standard Code for Information Interchange.

Computers can only understand numbers...
so, an ASCII code is the numerical representation of a character such as 'a' or '@' or an action of some sort.

ASCII was developed a long time ago and now the non-printing characters are rarely used for their original purpose.
Below is the ASCII character table and this includes descriptions of the first 32 non-printing characters.
ASCII was actually designed for use with teletypes and so the descriptions are somewhat obscure.
If someone says they want your CV however in ASCII format, all this means is they want 'plain' text with no formatting such as tabs, bold or underscoring - the raw format that any computer can understand.
This is usually so they can easily import the file into their own applications without issues.
Notepad.exe creates ASCII text, or in MS Word you can save a file as 'text only'.


Bits Reading

Binary 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111	Decimal 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15	Hexadecimal 0 1 2 3 4 5 6 7 8 9 A B C D E F

Definition:
Bits - the smallest unit of data in a computer. It is an acronym for binary digits.
Bytes - it contains 8 bits.
Hexadecimal format - the numbering system that involves the digits "0 though F".

Converting binary digits into decimal format:
Example:
01000001 to be converted into decimal number.

0 1 0 0 0 0 0 1

128 64 32 16 8 4 2 1

if the you total 1 + 64, it is equal to decimal 65.

Converting decimal to Hexadecimal format:
For example: decimal 65 to be converted hexadecimal format:
65 divided by 16
it is equal to the quotient 4 with remainder 1
so the hexadecimal format is equal to 41h.