PRBS (Pseudo-Random Binary Sequence)
In my line of work as a semiconductor test engineer, pseudo-random binary/bit sequences are very useful. They're random-ish streams of bits that can be easily and reliably reproduced using very simple hardware or software. Any semiconductor that can be used to transmit information can be tested at a functional level with a PRBS. Send a PRBS to the device you're testing, tell the device to repeat it back to you, and compare what you received to what you sent.
