Why does Emacs sometimes overwrite characters when I insert or delete? -

this happens me time. upon insertion/deletion, positions of other characters in buffer not shifted.

for example, buffer contents this important content, inserting very before important results in 2 words very , important appearing overlapped, this: this veryrtant content instead of this important content

how can fix this?

killing buffer , reopening of course works.

it sounds have accidentally turned on overwrite-mode.

that command toggle. bound default keys <insertchar> , <insert>. typically 1 of keys in keyboard key labeled insert.

but perhaps keyboard sending key when else.

does overwriting ever turn off? if so, suggest accidentally hit toggle key second time.

if not, perhaps keyboard or terminal somehow locked in overwriting mode. see same behavior outside of emacs?