The Teletype Model 33 provided a key labelled RUB OUT to punch this character (after the user backed up the tape using another button), and did not provide a key that produced the Backspace character (BS).
Therefore, a number of less-expensive computer systems that used Teletypes used this key (and thus the Delete code) to ignore the previous mis-typed character.
Video terminals designed to replace the teletype then had to place a key that produced this code where Backspace would be expected, in particular in products from Digital Equipment Corporation.
[4][5] On later terminals, such as the VT510, the key is labeled ⌫ (called backarrow in the manual[6]) and by default sent DEL, but could be set up to send BS.
Other terminals designed for systems that did not have a history of using Teletypes would usually make a key at this position send BS, leading to much confusion.
A key marked Backspace ← that sends BS is by far the most common on modern terminals and emulators.