What Does Keyboard Buffer Mean?
A keyboard buffer is a small area in the computer's memory (RAM) that is used to temporarily store the keystrokes from the keyboard before they are processed by the CPU. This is done because there is a delay between the pressing of the key and the sending of the signals, so to avoid timing issues, all the keystrokes are stored in the keyboard buffer until the user presses the "enter" key or a similar command which is very evident in command-line processing or time-sharing systems of generations past. But in today's modern computing environment with fast hardware and more memory, the keyboard buffer is not as obvious.
Techopedia Explains Keyboard Buffer
The keyboard buffer is used by the operating system to poll key strokes before processing the commands formed by those key presses. This is used to avoid premature processing of invalid commands and to avoid synchronization issues between the user and the computer, since without the buffer, a computer might be expecting a series of key presses from the user that does not come in time. A buffer which stores the typed characters, and essentially the commands, solves this issue of synchronization.
It is also a way to limit the input so that the computer is not flooded with inputs or interrupt requests, especially if a key combination is used for a specific command, such as the ctrl+alt+del command which brings up the task manager. If too many keys are pressed at once, the keyboard buffer returns an error and this is usually heard as a beep generated by the motherboard's built-in speaker. In older machines with slow CPU and RAM, it is possible for the user to type faster than the buffer can store the data, so an error is returned that the keyboard buffer is full. In this case, the user must simply type slower. However, this is no longer a problem in modern computers.