make config vs oldconfig vs defconfig vs menuconfig vs savedefconfig

make config:

• Options are prompted one after another.
• All options need to be answered

make menuconfig:

• Menu-driven user interface

make defconfig:

• Creates a ".config" file with default config from the ARCH defconfig

make oldconfig:

• Reads the existing .config file and prompts the user for options in the current kernel source not found in the .config file.
• Useful when you are moving the existing kernel configuration to a new kernel version.

make savedefconfig:

• Creates a 'defconfig' in the current directory.
• Used when you do a 'make defconfig' and modified few configuration changes

Ref: http://embeddedguruji.blogspot.com/2019/01/make-config-vs-oldconfig-vs-defconfig.html?m=0