What is the difference between make oldconfig and make menuconfig?

[Hao Lee]

I know make oldconfig is used to update my old .config to a newer one
and it will prompt me questions about the new configuration options.
However, make menuconfig can also handle old .config file properly and
it doesn't prompt any questions. I don't know what happened when
menuconfig processes my old .config file. Does it make decisions for
me automatically? Thanks.

Regards,
Hao Lee