Packet of Data: A unit of data that is transmitted over a network. Packet Header: The part of a packet that contains information about the packet, such as the source and destination addresses. Payload: The part of a packet that contains the actual data being transmitted. Trailer: The part of a packet that contains additional information, such as error checking codes. Destination Address: The address that specifies the recipient of a packet. Packet Number: A unique identifier assigned to each packet to help ensure that packets are received in the correct order. Originator’s Address: The address that specifies the sender of a packet. Packet Switching: A method of transmitting data in which packets are sent individually over a network and reassembled at the destination. Circuit Switching: A method of transmitting data in which a dedicated circuit is established between the sender and receiver. Data Transmission: The process of sending and receiving data over a network or communication channel. Serial Transmission: A method of data transmission in which data is sent one bit at a time over a single communication channel. Parallel Transmission: A method of data transmission in which multiple bits are sent simultaneously over multiple communication channels. Simplex Transmission: A method of data transmission in which data flows in only one direction, from sender to receiver. Half-duplex Transmission: A method of data transmission in which data can flow in both directions, but not simultaneously. Full-duplex Transmission: A method of data transmission in which data can flow in both directions simultaneously. Universal Serial Bus (USB): A standard interface for connecting devices to a computer, used for data transfer and charging. Data Transmission Errors: Errors that occur during the transmission of data, resulting in incorrect or incomplete data at the receiving end. Transmission Interference: The distortion or corruption of data during transmission due to interference from other signals or sources. Data Loss: The loss of data during transmission, due to errors or interference. Data Gain: The addition of data during transmission, due to errors or interference. Data Change: Alterations made to data during transmission, due to errors or interference. Parity Bit: An extra bit added to a binary code to ensure that the total number of ones in the code is either even or odd. Parity Byte: A byte containing a parity bit, used for error detection and correction. Parity Block: A block of data that includes one or more parity bytes, used for error detection and correction. Checksum: A value calculated from a block of data, used to detect errors or changes in the data. Echo Check: A method of error detection that involves sending a copy of the transmitted data back to the sender for comparison. Check Digit: A digit added to a number or code, used for error detection and correction. ISBN: International Standard Book Number, a unique identifier for books used in the publishing industry. Automatic Repeat Query (ARQ): A method of error control used in data transmission, in which the receiver requests the retransmission of data that is found to be incorrect or incomplete. ARQ Positive/Negative Acknowledgements: Signals sent by the receiver to the sender to indicate whether the received data was correct or incorrect. ARQ Timeout: The length of time a receiver will wait for a response from the sender before initiating a retransmission request. Encryption: The process of converting data into a secret code to protect its confidentiality. Asymmetric Encryption: A method of encryption that uses a pair of keys, one for encryption and one for decryption. Symmetric Encryption: A method of encryption that uses a single key for both encryption and decryption. Public Keys: Keys used in asymmetric encryption that are freely available and used to encrypt messages. Private Keys: Keys used in asymmetric encryption that are kept secret and used to decrypt messages.
