I went through a video on Youtube [2:42], that described "key difference" between a microcontroller and microprocess, apart from other differences, is that "microcontroller has a strong I/O capability so that they can derive external hardware directly, while microprocessor has weak I/O which needs transisitors to drive external hardware"

I really didnt understand why is that. Both microcontroller and microprocessor require transistors to drive external hardware. What am I missing?

This question is not pertaining to mere microcontrollers vs microprocessors, it is focused on a single distinction of "proficiency of driving external hardware"

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    \$\begingroup\$ I'm not going to watch the video, but that quote taken by itself sounds like nonsense to me. At the very least you need a specific definition of what "strong" and "weak" mean. \$\endgroup\$ Nov 15 '19 at 18:45
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    \$\begingroup\$ You're not missing anything. It's an overly generalized statement with plenty of exceptions, with the easiest counterexamples being microcontrollers with low voltage and current capabilities on output pins. \$\endgroup\$ Nov 15 '19 at 18:52
  • \$\begingroup\$ The video is incorrect and misleading. The only fundamental difference now MPU's at least access to memory expansion to run something of an operating system, e.g. RTOS or Linux \$\endgroup\$ Nov 15 '19 at 19:10
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    \$\begingroup\$ That only applies if there IS an OS, there doesn't have to be. The distinctions between microcontrollers and microprocessors are getting less pronounced, with all different nifty SOCs. Generally, the microcontroller tends to have more built in peripherals. \$\endgroup\$ Nov 15 '19 at 19:20
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    \$\begingroup\$ I understand what the quote is trying to say but it's not a useful distinction to make. Microprocessors are optimized for performance which means there's a greater chance that the GPIO will be lower currents (<5mA) and lower voltages (<3.3V) which makes it less useful in directly driving a minority of external hardware that can be driven directly from the GPIO (like LEDs). That said, I would not inherently expect every MCU to be able to source 10-20mA from its GPIO, though I would expect the drive voltages to be 3.3V-5V. But I would not be surprised to find more powerful MCUs that don't. \$\endgroup\$
    – DKNguyen
    Nov 15 '19 at 19:58