To find what command is bound to key, simply do C-h k key.
C-h k <left>:
<left> runs the command
left-char (found in
global-map), which is an
interactive compiled Lisp function in
It is bound to <left>.
(left-char &optional N)
N characters to the left (to the right if
N is negative).
On reaching beginning or end of buffer, stop and signal error.
visual-order-cursor-movement is non-nil, this always moves
to the left on display, wherever that is in the buffer.
Otherwise, depending on the bidirectional context, this may move
one position either backward or forward in the buffer. This is
in contrast with M-x forward-char and M-x backward-char, which
Try this for the other arrow keys.