Dumb terminals don't have disk drives or their own processors so they can't store files or do anything else on their own. Personal computers, on the other hand, can act as autonomous units which can be networked together. The copy information from one location to another without regard for its appearance or format. Often used for printing information that is temporarily useful. A term used in telecommunications to describe how signals are send.
Full duplex means that signals can be sent simultaneously back and forth.
Half duplex means that signals can go only in one direction at a time. A dynamic variable is a variable whose address is determined when the program is run. In contrast, a static variable has memory reserved for it at compilation time.