describe-mode function is used to provide information
about major modes. It is normally called with C-h m. The
describe-mode function uses the value of
which is why every major mode function needs to set the
This function displays the documentation of the current major mode.
describe-mode function calls the
function using the value of
major-mode as an argument. Thus, it
displays the documentation string of the major mode function.
(See Accessing Documentation.)
This variable holds the symbol for the current buffer’s major mode.
This symbol should have a function definition that is the command to
switch to that major mode. The
describe-mode function uses the
documentation string of the function as the documentation of the major