What are the advantages or disadvantages that using internal interrupt instead of external interrupt in MCU?
An external interrupt will use some external source (outside the microcontroller), such as a switch, motion sensor, or similar source, to trigger the interrupt.

An internal interrupt is triggered by some source inside the microcontroller, such as timer overflow, ADC data ready, UART data ready, etc.

Internal and External interrupts are not interchangeable - you have to use the one your interrupt source will trigger.

Edit:

I should have mentioned that what you do in the interrupt service routines will have much greater impact on the system performance than whether you use internal or external interrupts, as the main program will be paused while the interrupt service routine is running.