EBCDIC(pronounced “ebb see dick”) is short for extended binary coded decimal interchange code is eight bits, or one byte, wide. This is a coding system used to represent characters-letters, numerals, punctuation marks, and other symbols in computerized text. A character is represented in EBCDIC by eight bit. EBCDIC mainly used on IBM mainframe and IBM mid-range computer operating systems. Each byte consists of two nibbles, each four bits wide. The first four bits define the class of character, while the second nibble defines the specific character inside that class.
EBCDIC is different from, and incompatible with, the ASCII character set used by all other computers. The EBCDIC code allows for 256 different characters. For personal computers, however, ASCII is the standard. If you want to move text between your computer and a mainframe, you can get a file conversion utility that will convert between EBCDIC and ASCII.
EBCDIC was adapted from the character codes used in IBM’s per-electronic PUNCHED CARD machines, which made it less than ideal for modern computers. Among its many inconveniences were the use of non-contiguous codes for the alphabetic characters, and the absence of several punctuation characters such as the square brackets  used by much modern software.
For example, setting the first nibble to all-ones,1111, defines the character as a number, and the second nibble defines which number is encoded. EBCDIC can code up to 256 different characters.
There have been six or more incompatible versions of EBCDIC, the latest of which do include all the ASCII characters, but also contain characters that are not supported in ASCII.