There seems to be an error in the given answer. The correct answer would be C: Modem, not D: None of these. A modem is the device used to connect a computer to the internet or other computer networks through telephone or cable lines. Here is a detailed explanation of how a modem works and its importance in computer communication:
What is a Modem?
A modem, short for modulator-demodulator, is a hardware device that converts digital signals from a computer into analog signals that can be transmitted over telephone lines. It also performs the reverse function, converting analog signals received from the telephone lines back into digital signals that the computer can understand.
How does a Modem work?
1. Modulation: When a computer wants to send data, the modem first converts the digital information into analog signals using a process called modulation. It modulates the data by altering the frequency, amplitude, or phase of the analog carrier signal.
2. Transmission: The modulated analog signals are then transmitted over the telephone lines to the receiving modem at the other end.
3. Demodulation: Upon receiving the signals, the receiving modem demodulates the analog signals back into digital format by extracting and interpreting the original data.
4. Data Transfer: The demodulated digital signals are then delivered to the computer for processing and communication.
Importance of Modems in Computer Communication:
- Modems enable computers to connect to the internet or other computer networks through telephone lines, cable lines, or other communication channels.
- They allow users to access online resources, browse websites, send/receive emails, and engage in various online activities.
- Modems facilitate the transfer of data between computers, enabling communication, file sharing, and collaboration.
- They play a crucial role in remote access, allowing users to connect to their office networks or access their home computers from a remote location.
- Modems are also used in telecommunication systems to transmit data over long distances.
In conclusion, a modem is the device used to connect a computer to the internet or other computer networks through telephone or cable lines. It enables communication between computers by converting digital signals into analog signals for transmission and vice versa.