6. Identify the process of adding a value at the end of the sequence to ensure an input sequence by
a user is correct.

Validity check

Explanation:

We add something like CRC, Checksum, parity bit at the end of a sequence for ensuring the input sequence is correct. And an examination with the help of CRC,  Checksum or the parity bit is done by the receiver at the receiver end. And this is the validity check. And the code added is of two types, error detection code, and error detection and correction code.

answer inspecting packets in isolation from their context;