_________________ is used for the communication between computer and user.

____________is the point of interaction or communication between a computer and any other entity.

'Norton' is  ______________________.

_____________program is used to communicate with each other and to the hardware.

which system automatically checks out goods from a shop?

A man made program that enters our computer without us knowing about it.

Which device is used to send SMS and MMS?

This is often used for surveillance in areas which need security.

A telephone exchange that serves a particular business or office.

It make phone calls "work" in the sense of making connections and relaying the speech information.