ASCII means American Standard Code for Information Interchange. EBCDIC stands for Extended Binary Coded Decimal Interchange Code. One of the main differences between the two is the ASCII will only make use of seven bits in order to represent one character. The EBCDIC would need to use eight bits so that the character can be represented.
ASCII is normally used for encoding that is done in modern times. It can be common that people will consider this to be more efficient than others. EBCDIC is known to be used for IBM systems. The ASCII will be used to represent 128 characters, while EBCDIC can be used in order to represent 256 characters.