Communication mode which supports data in both directions at the same time is called

duplex mode

Explanation:

It is the duplex mode. In this mode, communication is in both directions at the same time. And it is different from the simplex or the semi duplex types in which the communication is one way only or one way at a time only. Thus, duplex mode seems to be requiring more bandwidth certainly but it can be advantageous definitely, and in situations like real tine communication, when we don't have the time and want to send as well receive the message at the same time.

i do not get the question.

the today function returns a valid value without any arguments.

the today function returns the current date based on the computer's date setting and formatted as a date. today takes no parameters, but requires that you use empty parentheses